Philadelphia Phillies left-hander Cole Hamels put on a pitching clinic Tuesday night. In eight innings, he struck out eight Cardinals batters and walked two, allowing just one run to cross home plate. His signature changeup was in fine form: According to Pitch F/X data from BrooksBaseball.net, Hamels threw 23 of his 28 changeups for a strike, and St. Louis hitters swung and missed at 11 of those off-speed offerings.

Expect more performances like this from Hamels in the days to come. Although the 26-year-old entered Tuesday’s action with a 5.06 ERA, he lowered that mark to 4.42 last night. And his peripheral stats suggest that he has been one of the best starters in the National League to this point.

In 38 2/3 innings, Hamels has whiffed 10.24 batters per nine innings, while allowing 2.79 walks per nine. Tim Lincecum, Jonathan Sanchez, Clayton Kershaw and Bud Norris are the only Senior Circuit pitchers with a higher K rate. Hamels is doing a great job of getting batters to chase his stuff off the plate, as opponents have swung at 31.6 percent of his pitches outside the strike zone. (The major league average this season is 27 percent.) That’s a career-best rate, and it places him in the top 10 among NL starters.

Despite the strong peripherals, Hamels’ numbers have been dragged down by abnormally high batting average on balls in play (BABIP) and home runs per fly ball figures. Hamels has suffered from a .356 BABIP in 2010, compared with a career .298 BABIP. Also obscuring his excellent pitching is a 16.7 percent home run per fly ball rate, well north of his career 11.9 percent clip and the league average, which typically sits in the 10-12 percent range. Hamels was also a bit unlucky last season, as his strikeout, walk and home run rates were virtually identical to his 2008 marks. However, his BABIP went from .270 to .325, and his ERA jumped from 3.09 to 4.32.

With fewer bloop hits falling in and fly balls finding the stands less often, Hamels should see his ERA dip this season. He currently holds a 3.31 expected fielding-independent ERA (xFIP), which gauges a pitcher’s performance based on strikeouts, walks and a normal home run per fly ball rate. That places Hamels seventh among NL starters.

Roy Halladay may be the talk of the town, but Hamels gives the Phillies a second ace.

Not long ago, Denard Span looked like nothing more than a grade C prospect who failed to make good on his tremendous athletic ability. Then, something changed, and quickly. Span developed a more patient approach at the plate, which led to him drawing more walks and getting better pitches to hit. Fast-forwarding to today, Span is an extremely valuable regular on a winning team. Breakouts can seemingly come from out of nowhere, but there are statistical indicators that tell us which are more real than others.

Naturally, at this time of the year we view players with a certain air of suspicion, and rightly so; Small sample sizes make trusting early season statistics difficult. However, there is a point in time when certain stats can become more trustworthy than others. A study done by Russell Carlton showed that after 50 plate appearances, a player’s swing habits can be a reliable guide to what’s going on. In the case of Colby Rasmus, his swing habits give us a substantial reason to believe he’s a changed man. According to O-Swing percentage (which is a stat we use at FanGraphs that measures the percentage of swings a batter takes at pitches outside of the strike zone), undisciplined batters greatly decrease their odds of reaching base by mercilessly hacking at everything thrown their direction. (This shouldn’t surprise anyone.) Rasmus did not really show great plate discipline last season, evidenced by a paltry .307 on-base percentage. He swung at 25.9 percent of pitches thrown out of the zone last year, but this season, he’s decreased that number to just 17.8 percent. As a result, Rasmus has drawn more walks (17) than teammate Albert Pujols (15) and he’s taking more advantage of pitches he’s finding to his liking. The result? A line of .316/.436/.658. People have projected stardom for Rasmus since he was a first-round pick in 2005, and it appears the 23-year-old is figuring things out.

Like Rasmus, Oakland’s Daric Barton is also demonstrating a tremendous amount of selectivity at the plate, with an O-Swing percentage of just 13 percent. Barton’s been known for this for a while, but he is also making a lot more contact when he does swing. He’s getting the bat on the ball 89.7 percent of the time when he swings, a 4.8 percent increase over his career rates. When you’re not swinging at a lot of bad pitches, and making that much contact with the pitches you do swing at, good things are bound to happen, and they are so far for Barton. He’s never going to hit for a ton of power, but he has a .407 OBP and should be an on-base machine for years to come.

Chicago Cubs left-handed reliever Sean Marshall is another breakout to believe in. In the early goings of the season, we see that his curve has about 2 more inches of downward movement according to Pitch f/x data, and he’s throwing his curve 41.5 percent of the time. Batters against Marshall have an O-Swing percentage of 33.0 this season, and his career rate is 23.0. Translation: He’s getting a lot more guys to chase out of the zone, because he’s throwing a curve with more movement. While he’s not going to be confused with a flamethrower anytime soon, his average fastball velocity is up from 87 mph to 89.3 mph, a considerable increase. A better fastball helps set up the off-speed, and it helps when that off-speed pitch is a filthy, knee-buckling curveball like Marshall’s. He’s fanned 18 and walked just two batters in 14 innings, and his dominance could give the Cubs the flexibility to move Carlos Zambrano back into the rotation.

On the heels of Ryan Ludwick’s somewhat innocuous 1-for-3 performance Sunday against the Reds, it might seem odd to focus on the Cardinals right fielder today. But there was a lot of intrigue in those few at-bats, and a lot of food for thought.

Ludwick’s strong season to date has garnered some notice. He is batting .290, he’s walking more than 10 percent of the time, and he has an isolated power above .190. These all are benchmarks he met back in the halcyon days of yore (aka 2008, when he also hit 37 home runs), but fell short of last year. So what has changed?

For starters, manager Tony La Russa has him hitting second this year after usually batting him fourth or fifth the past two seasons. The stated reason for the switch was to get Ludwick more fastballs while hitting in front of Albert Pujols. So far, so good. Thus far, Ludwick is seeing fastballs 57 percent of the time, which is the most he’s seen in five years. In Sunday’s win against Cincy, 10 of the 13 pitches Ludwick got were fastballs.

This would seem like a silly new strategy because Ludwick crushes fastballs. A statistic on FanGraphs measures a batters’ effectiveness versus each type of pitch and produces a runs above average figure for each offering. In his career, Ludwick has been most successful against the fastball, to the tune of 53 runs above average. Compare that to his success against the curve (plus-3 runs) and the change (plus-7.8 runs), and you get a sense of how much he enjoys the fastball. His run-producing single Sunday came on a fastball.

So why are pitchers throwing him the fastball? Convention wisdom says that Pujols lurking in the on-deck circle has something to do with it. Fastballs find the strike zone 54.1 percent of the time across baseball, compared to 44.7 percent of the time for curveballs and 42.9 percent of the time for changeups. (Thanks to Daniel Moroz of Beyond the Box Score for those numbers.) If pitchers are worried about Pujols coming up next, it makes sense they’d want to make sure not to walk Ludwick and use a pitch that they could command against him.

Lineup protection is an easy explanation for all the fastballs Ludwick is seeing, but there has been research that shows that lineup protection is a myth. Whether you are inclined to believe J.C. Bradbury or conventional wisdom of lineup protection, the bottom line is that Ludwick is seeing more fastball this year. And that’s a boon to his bottom line.

Austin Jackson is an interesting ballplayer. The Detroit Tigers center fielder is hitting .330/.394/.468 out of the leadoff spot. And thought the ultra-athletic rookie is far from a finished product, you can’t argue with his numbers thus far. But how about this one: 34 percent. As in, the 23-year-old is striking out in 34 percent of his plate appearances. That’s Mark Reynolds‘ territory. Jackson is being talked about as a rookie of the year contender, but can he sustain his excellence with his current strikeout rate?

The most obvious reason to doubt Jackson is his batting average on balls in play, which currently sits at .492 and is the highest in baseball. Last year, the league leader in BABIP was David Wright at .394, so we can expect Jackson’s BABIP to come crashing down. But it appears his high BABIP is a little more than just luck, and is a byproduct of the way he is being pitched.

Like a lot of young players, Jackson clearly enjoys hitting the fastball. A look at his pitch-type values shows that he’s 0.93 runs above average (per 100 pitches) against the heater. Compare that to a -1.68 against changeups, and you suddenly have a pretty good idea of what to throw to Jackson. In his column today, Tim Kurkjian discusses the fundamental failings of some of the game’s top young players, and Jackson’s inability to hit off-speed stuff fits that topic. So far this season, Jackson has been seeing a large number of fastballs, as pitchers are no doubt testing the young hitter. He’s been challenged with the heat 68 percent of the time. In contrast, teammate Miguel Cabrera — a proven fastball hitter — has seen 56 percent fastballs. Jackson has been thrown changeups 11 percent of the time, and we should see that number continue to rise as opponents figure out his weakness. Also, Jackson swings at pitches outside the strike zone just 1.0 percent more often than the league average. However, he has a significant issue with making contact on pitches outside the zone: 57.9 percent compared to an average of 64.5 percent.

It’s clear that Jackson needs to make some adjustments if he’s still going to be in the AL Rookie of the Year race in September. As a leadoff catalyst, his job is to get on base and into scoring position for the club’s run producers. A player with a strikeout rate of more than 30 percent is not going to get the job done over the course of a full season. If we regress Jackson’s BABIP to a still-high .380, he’s going to produce an on-base percentage around .323. If we lower his BABIP to the current league-average of approximately .300, his OBP suddenly becomes a welcome-back-to-the-minors .276.

The scouting report on Jackson is no doubt filtering through the league as we speak: Changeups, preferably out of the zone. It will be up to the rookie to adjust. If he doesn’t, the next five months of the season will be rough when his BABIP comes back down to earth.

The designated hitter spot presents American League teams with an opportunity that their NL brethren don’t get to take advantage of. This seems like an advantage that every team should exploit, but as we’ve seen so far in 2010, that doesn’t always happen.

Thus far this season DHs are hitting a combined .246/.336/.412 in 1,228 plate appearances, which is pretty much league average. In terms of batting average, only catchers have fared worse. The DH spot ranks fourth in OBP, behind right field, left field, and first base, and ranks fifth in slugging, behind those same positions plus center field. Shouldn’t players who have no responsibilities other than to hit perform better than their two-way counterparts? Theoretically this is the case, but in practice, a number of teams end up featuring former stars with big contracts in the DH role, because they have no other place to play them.

The A’s, Red Sox, and Indians have suffered their most from their designated “hitters.” Eric Chavez ranks the best among the three with a .236/.279/.345 line. The other two, David Ortiz and Travis Hafner, have combined for a .180/.273/.324 mark, not much better than what those teams would get if they let their pitchers hit. Normally players who produce these numbers would sit on the bench, but these three players will make a combined $36 million in 2010. While continued poor production might force Ortiz and Chavez from the lineup since their contracts expire after this season, Hafner has two years and $28.75 million left on his deal. The Indians will probably give him every chance to revert to his former self.

A few years ago, Ortiz and Hafner received big-money deals to exclusively serve as DH, but as baseball puts a greater emphasis on defense, we’ll see if players with no value in the field continued to be paid like stars. Considering Jermaine Dye hasn’t been able to find a deal to his liking, it seems unlikely.

Both Felix Hernandez and Josh Beckett were given hefty contract extensions this past offseason, with both of their teams paying them to pitch like aces. Both right-handers were on the mound Monday night, and while one of them is looking like a very wise investment, the other is not. And there’s a pretty simple explanation as to why.

King Felix drew the Kansas City Royals to close out his April slate and held the hot-hitting Royals to two earned runs through seven innings. Hernandez did walk three but also struck out seven. The most notable thing about his outing — besides the fact that his team failed to score while he was in the game — was his ground-ball rate. Prior to the start, 62 percent of batted balls against Hernandez this season were of the ground-ball variety, a mark that will represent a career high if it holds up. (His career ground-ball rate is 57 percent.) On Monday night, 14 of the 23 balls put into play by the Royals were on the ground — or roughly 61 percent.

The reason for Hernandez’s increased ground-ball rate is his increased sinker velocity. Pitch f/x data collected from the 2009 and 2010 seasons says Hernandez is throwing his sinker nearly 94 mph on average thus far this season, while the pitch was closer to 90 mph last season. The 24-year-old might lose some velocity over the grind of a long season, but for now, Herandez’s sinker is simply overpowering hitters, and his 2.15 ERA suggests as much.

As for Beckett, he was striking out just 5.96 batters per nine innings entering Monday’s affair with the Toronto Blue Jays and had a 5.26 ERA. The Jays lead the league in strikeout percentage, making them the perfect opponent for Beckett to rack up some K’s against, right? Wrong. Beckett lasted all of three innings while allowing eight earned runs on nine hits to go with three strikeouts, three walks and a home run allowed. His ERA is now 7.22.

The biggest shifts in Beckett’s game are an increased number of changeups and a decreased number of swinging strikes. Beckett is using his changeup more than he ever has with Boston, and the results have not been pretty. FanGraphs’ run values suggest the changeup is his worst pitch on a rate basis, and it’s not particularly close. For every 100 changeups, Beckett is costing his team nearly three runs. What’s odd about that is last year, when Beckett had a 3.86 ERA, his change was his most valuable pitch. For every 100 times thrown, it was worth 2.16 runs. This year, he is throwing it more than 14 percent of the time. Last year, he threw it 8.6 percent of the time. Obviously, something is wrong with the offering. And a look at the chart below tells the story: Beckett is leaving his changeup up in the zone far more frequently.

Meanwhile, only 7.4 percent of Beckett’s pitches are resulting in swings and misses, a stark contrast to his career percentage of 9.9 percentage. Swinging strikes correlate pretty well with strikeouts, so this is not what Boston wants to see from its $68 million-dollar man.

In both cases, the alterations to their pitch repertoires and the contrasting degrees of success could be just coincidence or small sample sizes playing with the numbers. Whatever the truth is, both the Red Sox and Mariners will need their aces to thrive if their playoff hopes are to be categorized as anything but just hopes.

The San Diego Padres lost Sunday. This qualifies as news because lately they’ve been playing like the best team in baseball. Before Sunday’s loss, the Padres had won eight consecutive games, including sweeps of divisional foes Arizona and San Francisco. And in ESPN.com’s latest MLB Power Rankings, San Diego is No. 7.

Although superstar first baseman Adrian Gonzalez is doing his thing, hitting home runs in each of the past four games, the key to the Padres’ early success is a bunch of no-names.

Chase Headley, a former hotshot prospect who previously struggled to adjust to the big leagues, has found his stroke in April. His .371 batting average easily paces the team. Although the third baseman is not a huge power threat, he has seven extra-base hits and six stolen bases, providing all-around value. Based on FanGraphs’ wins above replacement statistic, Headley has been worth 1.1 wins (compared with Gonzalez’s 1.0), making him the team’s co-MVP through the first three weeks of the season.

Headley isn’t the only low-profile guy carrying his weight. Outfielder Will Venable has provided some much-needed power to a lineup that lacks punch beyond Gonzalez. His .262 average might not look like much on the surface, but nine of his 16 hits have gone for extra bases, giving him a ridiculous .312 isolated slugging percentage on the season. (Isolated slugging is simply slugging minus batting average, which allows us to measure the power output of a player by excluding singles.) For comparison, Prince Fielder of the Milwaukee Brewers posted a .303 ISO last season.

Wrapping up the trio of unheralded early-season Padres hitting stars is catcher Nick Hundley. Like Venable, his .262 batting average isn’t all that impressive, but instead of supplying power, Hundley is busting out the walking stick. He’s drawn eight free passes in 13 games, driving his on-base percentage up to .380, a remarkably high number for a backstop. Although the base on balls is a less sexy way to derive value, there is no more important offensive skill than the ability to get on base.

It’s unlikely that Headley, Venable and Hundley will continue to perform like stars because none of them has a track record that suggests he can sustain his performance. But if you’re looking for the reason the Padres are in first place, look no further than these three. And considering none of the members of the trio is older than 27, it’s possible they’ve turned a corner in their development. If they all continue on their current career-year course, the NL West will be a lot more interesting.

Livan Hernandez saw his unlikely scoreless streak end at 17 innings yesterday, as he gave up the first of two solo home runs that would give him his first loss of the season. It was the kind of start that serves as a lesson for why wins and losses don’t matter, as the Nationals offered no run support. But the loss does nothing to taint what has been the best April of Livan’s career, coming in a season where even the most optimistic of projection systems saw him as a 5.00 ERA pitcher. There are a lot of explanations for why Hernandez won’t be sustain his success going forward — his 9-7 strikeout-to-walk ratio, for instance — but none more so than a hitless streak that would make Ubaldo Jimenez jealous.

Hernandez has pitched from the stretch in 29 plate appearances this season, and in none of those has he allowed a hit. In all, opponents are hitting a ridiculous .000/.138/.000 when their teammates are on base against Livan, which explains why two solo home runs on Thursday are the only runs that have crossed the plate in the 24 innings Hernandez has pitched this season.

At FanGraphs, we track a stat called Left on Base Percentage, which monitors the rate that pitchers strand baserunners. League averages usually hover between 70 and 72 percent, and while better pitchers can routinely be above-average, pitchers of Livan’s ilk see a great deal of variance. Stranding runners is a huge part of run prevention, which is why the season Hernandez had his best LOB% (2003 – 78.7 percent) corresponded with his best full-season ERA (3.20). And the year of his worst LOB% (2008 – 64.8 percent) led to a career-worst ERA (6.05). This season, Livan’s Left on Base Percentage is a perfect 100 percent, a rate difficult to sustain for three starts, much less an entire season.

In his career, which spans 2,750 innings, Livan has been identical with the bases empty (.780 OPS allowed) and with runners on base (.782 OPS allowed). His stuff doesn’t get better from the stretch, his delivery isn’t more deceptive. People will say that Hernandez is succeeding because he is “bearing down” with runners on base. This is not true. He is merely in the midst of an amazing stretch of good fortune. While a career revival makes a good story, this is a tale more likely to end with regression to the mean, and another below-average, innings-eating season for Hernandez.

What would you have said if I had told you before the season began that the Padres would be leading the NL West on April 22? Odds are you would have called me crazy, and justifiably so. But here we are, and that’s because crazy things happen, especially in short time frames.

While what has happened so far can’t be taken as gospel of what will happen over the rest of the season, we can see that some things have shifted. By looking back at preseason projections and applying them to what has already occurred, we can get an updated look at how teams and players may perform this year. To explain the methodology, I’m going to use the Phillies as an example.

In the April 5 edition of ESPN The Magazine, Dan Szymborski’s ZiPS projections predicted that Philadelphia would win about 93 games. They have won 9 of their first 14 games already, so does that mean they are going to win 84 games the rest of the year to bring their total to 93? No. We wouldn’t expect them to play worse the rest of the year just because they got off to a good start.

Our best assumption is that they are still a 93-win team the rest of the way, so we simply take their projected win percentage (.571) and apply it to their remaining games (148), making their updated projection 94 wins. They have added a win to their preseason expected total by playing so well in the first two weeks of the season.

For an updated look at how ZiPS thinks your team will finish the season, here are the updated projected standings through April 20, rounded to the nearest win:

Even though they are currently leading the NL West, the Padres are still projected as the third-worst team in the majors, behind the Blue Jays and Astros. The Jays are also off to a good start (9-7), but keep in mind that they have yet to play the Yankees, Rays or Red Sox.

The Red Sox’s falling into third place was the only major change when comparing the update with the original predictions. For the preseason ZiPS predictions in The Mag, the Red Sox were projected to win the AL East. After their slow start, they are now projected to miss the playoffs. That slow start created a large hole that they now have to dig out of, and with two good teams in the division, it won’t be easy. While Boston’s slow start isn’t reflective of how good the Sox are as a team, their place in the standings may just be “real,” because they now have to play better than their true talent level in order to close the gap. They may be able to do it, but it will now be an upset if the Red Sox make the playoffs.

Kosuke Fukudome wasted no time winning Cubs’ fans hearts in 2008, hitting a game-tying three-run home run in his major league debut, and blistering the baseball in his first month in the majors. At the end of his first April, he was hitting .327/.436/.480 and looked like a star.

The rest of the season didn’t go quite as well. Fukudome hit .241/.340/.355 from May through September, showing little power and earning a late season benching. In 2009 we saw much of the same. In his 89 April plate appearances Fukudome hit .338/.461/.592, an improvement even over his hot April 2008. The rest of the way he hit .245/.360/.393, again a bit better than 2008 but still a disappointment after another torrid start.

He’s again off to a good start — he’s hitting .297 — yet Cubs fans have been conditioned to expect much worse once the calendar turns to May. Why has he hit so much better in April than the rest of the year?

It is tough to assign cause to such a small sample, however, we can see a discrepancy in his batted ball types in April compared to the rest of the season. In the first month of the year, Fukudome hits the ball in the air and drives it with some regularity, as seen in the graph below. It shows the percentage of flyballs to each zone divided by total balls in play, with the colors showing slugging percentage — the redder the better. As you can see, he turns into a groundball machine as the season wears on. And after driving the ball to right field seven percent of the time in April, that number drops to three percent the rest of the year.

If you’re more of a numbers person than a graph person, Fukudome’s career GB percentage in April is 41 percent, compared with 50 percent the rest of the year.

At a glance, it might seem like hitting ground balls isn’t all a bad thing. Ground balls, after all, produce hits at a greater rate than fly balls. But that only touches on one dimension of hitting — and even then, it’s not a particularly compelling argument. Last year in the National League ground balls produced a .234 batting average, while fly balls produced a .224 average. (Line drives, the third type of batted ball, had a .728 average.) But slugging percentage on fly balls is considerably higher than on grounders. NL hitters slugged .595 on fly balls last season, while they slugged just .255 on ground balls. It’s pretty hard to hit a groundball over the wall.

While some hitters can benefit from hitting the ball on the ground, Fukudome does not profile as one of them. He possesses the power to hit near or in the middle of the order, having hit 31 homers for the Chunichi Dragons in 2006. However, he doesn’t take advantage of this power once the calendar flips to May. He’s off to a strong start again, and he has kept the ball in the air at a greater frequency than in his past two seasons. Maybe it’s Fukudome’s year, but until he shows the ability to hit fly balls and line drives in the later months, don’t expect an improvement.