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Jay Bruce and the Problem with Player Evaluation

From the start, Jay Bruce has done just what every fan wants to see from a young player who just signed a contract extension. He started out on fire, going 15 for his first 30, with three doubles and four homers. Of course, a .500/.531/1.000 line wouldn’t last forever, but it put everyone at ease, especially after his .306/.376/.575 line in the second half of 2010. He has streaked and slumped a bit since then, as one might expect. After an 0-for-3 performance last night he’s down to .282/.349/.535, though those are still quite excellent numbers — a .386 wOBA, which ranks sixth among NL outfielders. If he catches fire again, he could start climbing that leaderboard again.

Only, that’s not exactly true. Yes, Bruce does have a .386 wOBA, and that does rank sixth among NL outfielders. But it took Bruce a while to get there. In fact, the streak described above is currently happening, while the slump, including that 0-for-3 performance, occurred a bit earlier in the season. It doesn’t change the end result, but it does change the narrative.

Right now Bruce is at or above the level of play expected of him, but it took him a while to get there. He started the season in a pretty massive slump, going 9 for his first 41 with two doubles and three walks. It wasn’t until his 49th plate appearance that he smacked his first home run, a tack-on at the end of a 6-1 victory over the Pirates. It was the day after that homer that our own Howard Bender, writing for RotoGraphs, preached patience with young Bruce. It was clearly the right message, since his season started to turn around right there.

Still, it wasn’t a smooth transition back to the top. After a mini surge Bruce again fell into a slump, and after going 0-for-3 with a walk on April 26th he was hitting just .226/.290/.357. It took him a while even then to pick himself up; as recently as May 14th he was hitting .236/.312/.436. But then he went on the above-described surge, which has essentially corrected the wrongs of the early season and has placed him back in the company of the league’s elite outfielders.

I have to wonder how a change in the order of how Bruce got to this point changes the narrative of his season. When I first started this, it was a bit on how this recent surge has taken pedestrian numbers and turned them into superstar numbers. And, of course, because hot streaks don’t last forever it’s easy to say that he’ll cool down, and his wOBA will drop a bit. But then re-read the first paragraph. It just changes the order of events to have the streak come first, followed by the slump. In that scenario, we might expect Bruce to go on a surge again sometime soon — slumps don’t last forever, either.

The fickle nature of small samples makes analyzing players difficult at this point in the season. It feels in many cases as though we’re telling a story about a player, or describing a certain process, rather than pinning down anything predictive. That’s just the nature of the beast. Bruce might be the best example of that. There is absolutely no telling where his season ends up. Maybe he’ll continue this streak, bring his wOBA up to .420 or so, and then cool back down and stay at the .386 level. Maybe he’ll cool down in the next few games and settle at around .363, as he did last year. There’s no real way to tell, given the information we currently have available. That doesn’t diminish Bruce’s surge-and-slump season. It just highlights an issue we all face when evaluating player performance, even at the 200 PA mark.