How Much Was Luck a Factor in Jeff Keppinger’s Breakout Season?


Last January, the Rays signed infielder Jeff Keppinger to a one-year contract. Keppinger’s role was unclear with the Rays apparently set at the two position Keppinger can play, third base and second base, were occupied by Evan Longoria and Ben Zobrist. But thanks to injury and poor performance, Keppinger was forced into a starting role for the Rays almost the entire season, and he came through with a breakthrough season. Keppinger posted a .325/.367/.439 (127 OPS+) line with 15 doubles, 9 homers, 40 RBI, and 31 strikeouts against 24 walks in 115 game and 418 plate appearances. But how did Keppinger pull it off? He entered the season with just a .281/.332/388 line (92 OPS+). Did Keppinger really figure something out or was he just lucky all season?

Keppinger’s BAbip (batting average on balls in play) in 2012 was .332, solidly above his .294 career mark. Part of the explanation is that Keppinger’s line drive rate in 2012 was 20%, a tick above his 19% career mark, but that certainly doesn’t account for such a big difference in BAbip. In fact, 16% of Keppinger’s flyballs were pop-ups on the infield (and basically automatic outs), easily the highest mark of any season of his career and nearly doubling his 9% mark from 2007 to 2011. How did Keppinger manage to cancel out so many pop-ups and not that many line drives to hit for such a high batting average and BAbip? Something immediately stands out: Keppinger had 20 infield hits, shockingly the most on the Rays, one more than both B.J. Upton and Ben Zobrist. Jeff Keppinger stole just 1 base, so he’s not exactly a speed demon, so how in the world did that happen?

On the season, Keppinger had a .251 BAbip on groundballs, a .113 BAbip on flyballs, and a .822 BAbip on line drives. What does that mean? For perspective, Keppinger has career .224 BAbip on groundballs, a .135 BAbip on flyballs, and a .702 BAbip on line drives, and the AL average in 2012 was a .237 BAbip on grounders, a .127 BAbip on flyballs, and a .709 BAbip on line drives. Looking at that, Keppinger was well above both his career and the league average in terms of BAbip on both groundballs and line drives while coming in decently below the average on flyballs. Particularly the difference from his 2012 line drive rate especially stands out as there’s just a .01 probability of his BAbip on line drives being as high as .822 if it’s true value should be .702. But the problem with splitting up BAbip by batted ball type like this is that all batted balls on the same type are not created equal. For example, there are line drives that would go for singles if they drop in and line drives that are lasers heading to the gaps for extra base hits. Looking at Keppinger’s batted ball tendencies, how did his batted balls differ from his career average and the career average?

Keppinger’s inflated BAbip on groundballs clearly has a lot to do with the 20 infield singles. Taking out the infield singles, his BAbip on groundballs would be just .157, which comes in below the league average of .169 without infield singles. But both with and without infield hits being part of the equation, a higher proportion of Keppinger’s groundballs went for extra-base hits than the league average, 8.8% compared to the 8.1% league average with the infield hits, and 20% compared to the 12.4% without them. The problem is that the sample size is so small- the entirety of Keppinger’s extra-base hits on groundballs was 4 doubles. However, it may be that Keppinger’s success on groundballs this season is that he was hitting groundballs harder than the average player, making them more likely to be singles. But we saw that so many of Keppinger’s groundball hits were infield singles, and don’t hard-hit groundballs that stay on the infield often turn into routine plays? That is the case once the fielder is able to come up with groundballs because he has plenty of time to throw. However, it does become harder for him to feel the ball cleanly. One thing that stands out about Keppinger’s season is that he didn’t reach on an error all season. Several of his infield hits had to be plays that could have scored errors or hits and were ruled hits. That means that Keppinger’s batting average should almost definitely be at least a few points lower than the .325 mark where it ended up. But it can’t be a bad thing that Keppinger has been hitting the ball harder, and although a disproportionate amount of his groundball hits came on the infield this season, that could be rectified without his BAbip on groundballs going down too much in coming seasons.

In terms of line drives, the exact opposite phenomenon is happening. Keppinger’s BAbip on line drives (.822) was so much higher than his career average (.702) and the league average (.709), but a much lower percentage of his line drive hits went for extra-base hits. Just 9.6% of his line drives were extra-base hits, less the half the league average of 20.5% and well below his 15.9% career average. (Note that we were using percentage of groundballs hits before and we’re the using percentage of Keppinger’s total line drives). Keppinger’s BAbip on line drives was very high, but watching baseball it does make sense that line drives into the shallow outfield are more likely to drop than ones to the deeper outfield because if you can get it past the infield, there’s a big gap between the infielders and the outfielders. Keppinger did hit a little bit more extra-base hits on flyballs than his career average, 13.2% of his flyballs compared to his 12.5% career average, although that’s still solidly below the AL average of 17.2% in 2012.

What really happened in 2012 is that Jeff Keppinger decided to trade most of the little power he has in exchange for hitting balls harder, albeit for singles more than anything else. Just 20% of Keppinger’s hits went for extra bases, his lowest mark since 2004, but it didn’t matter as Keppinger’s overall offensive performance was better than anything we’ve ever seen from him before. Weak groundballs are often the case of taking a big swing and being out in front and rolling over the ball. Keppinger didn’t take many big swings and was content just putting the ball in play and hitting the ball hard wherever he could, and the results were outstanding. Can Keppinger sustain anywhere near his 2012 performance? He’s likely due for a regression in terms of his BAbip on groundballs, and although his high BAbip on line drives makes sense, he will likely go down in that regard as well moving forward. But Keppinger made a big realization in 2012 as to what type of player he needs to be to achieve the most success, and whether his future comes in Tampa Bay or elsewhere, Keppinger will view this 2012 season with the Rays as a turning point.