InDepth Spotlight: Dan Haren vs. David DeJesus

In tonight's A's-Angels game, keep an eye on how L.A.'s Dan Haren pitches to Oakland leadoff hitter David DeJesus. Haren has been relying heavily on his cutter this season, throwing it 35.1% of the time, the most of any pitch. The results have been good; opposing batters have hit only .148 against the pitch (4 hits, 27 PA, 68 total pitches).

Meanwhile, DeJesus has not hit cutters well in his career.

David Dejesus vs. Cutters (2008-Present) (Click to enlarge) DeJesus has hit only .171 against cutters since 2008, with no extra base hits (6 hits, 38 PA, 165 total pitches). Against righty cutters, he's only hitting .130. Expect Haren to lean heavily on the pitch when DeJesus is in the batter's box tonight.

Trevor Cahill's Sinker: Luck or Skill?

Trevor Cahill had a fantastic year for the Oakland A's in 2010.  He was very successful in keeping the ball down, as he went from a 96 ERA+ in 2009 to a 136 ERA+ last season.  Some have noted that his very low overall BABIP (.237) is partially responsible for his success, rather than any particular ability to induce weak ground balls.  However, a closer look possibly indicates that luck may not have played as big a role in Cahill's success.

Cahill was one of the most successful ground ball pitchers in the majors; 56% of batted balls off his pitches ended up on the ground in 2010, 5th highest in the majors.  As you can see from the heat map above, he became very efficient at keeping his pitches down last season.  His GB/FB ratio went from .92 to 1.32 in one year.  The main reason: his excellent sinker.

Cahill's 2010 sinker was flat out nasty, averaging 14.8 feet per second of downward movement, putting him in the top 10 percent of sinkerballers.  This makes it tougher to chalk up his basement low .153 batting average on ground balls (best in the majors) to mostly luck.  He's obviously benefitting greatly from the movement he's getting on his sinker. If batters are finding it harder to makes solid contact as a result of that increased movement, it's possible they are hitting weaker ground balls; in turn, this would make it easier for his defense to field and turn these ground balls into outs. 

This is not to say that we won't see some regression this year.  It's certainly possible that a good chunk of these ground balls were simply finding infielders, particularly when well hit. But if he can keep his pitches down and moving as they did last year, don't be surprised if his overall BABIP remains in the cellar.

Conor's Eye for the Corner

Conor Jackson was riding high coming out of the 2008 season.  He was in his prime at age 26 and posted a .300/.376/.446 slash line, with his BA and OBP setting career highs.  Illness and injury set him back the last two seasons, however.  His .218/.313/.303 line since the start of 2009 won't impress anyone.  Now with the Oakland Athletics, a return to health might mean a return to great hitting.

There is a change in Jackson that might help him crack the starting lineup.  Through his illness, his batting eye improved.  In 2008, look where he swung and took the most:

Conor Jackson, pitch frequency on swings, 2008Conor Jackson, pitch frequency taking pitches, 2008Conor likes to swing at pitches up in the strike zone.  Although not shown here, he tends to swing at pitches that drop less than expected, and takes pitches that drop more than expected.  That remained true in 2009-2010, but he started laying off pitches on the low outside corner in the strike zone.

Conor Jackson, pitch frequency on swings, 2009-2010Conor Jackson, pitch frequency taking pitches, 2009-2010He's more willing to go after low pitches, and he's taking fewer in the zone.  Better strike zone judgment means more walks, and maybe more calls his way.

On the other hand, it could be he doesn't hit the low, outside pitch all that well, and he's better off waiting for something up higher.  We'll see.  The Athletics are big on process, and someone who takes a ball and swings at a strike should do well in their system.