Friend of the blog Steve H made a fascinating comparison on Twitter last night that highlights the power of perception and narrative in sports:

Player A: 74.2 IP, 9.16 K/9, 3.62 BB/9, .72 HR/9, 1.93 ERA, 3.37 FIP, 3.59 xFIP
Player B: 71.2 IP, 9.67 K/9, 2.76 BB/9, .75 HR/9, 4.40 ERA, 2.98 FIP, 3.34 xFIP

The analysis here is pretty simple. The two players are very similar across the board, with the peripherals favoring Player B by a bit. The difference, of course, comes from Player B having a .342 BABIP (20 points above his career levels) and a 66.6 LOB%, compared to a .225 BABIP and 86.0 LOB% for Player A. Basically, Player A was lucky while Player B was unlucky, such that the perception of the two players is vastly different despite very similar performances.

Player A is Daniel Bard. Bard is seen as a relief ace, and many thought the Red Sox might non-tender Jonathan Papelbon and let Bard take over the closer role on a potential playoff team. He is certainly the closer-in-waiting, and is perceived as being one of the hot young arms in the sport.

Player B is Joba Chamberlain, who is viewed by many to be a massive disappointment. A “failure” as a starter and underwhelming last season as a reliever, he has become the player most frequently inserted into random trade proposals by Yankees fans. Some have suggested that the Yankees do not see him as being a big part of their future, and his stock is certainly far lower than Bard’s.

And yet, the numbers show that Joba was about as good as Bard was last season, and that with a little bit of luck, the perception about him would likely be vastly different. Furthermore, Bard is actually 3 months older than Chamberlain, a fact that would surprise most but suggests that they are on equal footing in terms of development. I do not mean to suggest that Joba was actually better than Bard in 2010, as there is something to be said for ERA and results, such that I would not explain all of Joba’s struggles away using the “luck” factor. But the peripherals clearly tell us that these two pitchers should be regarded similarly, and I would be far from shocked if Joba and Bard put forth extremely similar seasons in 2011.