Wednesday, September 19, 2007

Tejada and Changing Positions

There has been increasing speculation around the Orioles that if Miguel Tejada is on the team next season, it will be at another position, possibly 3B. Jeff Zrebiec wrote an illuminating article in The Sun about the issue yesterday.

The saying is that where there's smoke, there's fire. That might not be the case here, but it's almost undoubtedly true that the some of the folks running the club can envision a scenario where Luis Hernandez takes over as the everyday SS next season. If that's the case, it's very disturbing whether or not Hernandez eventually gets the job or not.

The idea that Hernandez is a viable SS candidate at this point rejects nearly every accepted notion about the value of defense relative to offense, the tradeoffs between the two, and the utility of minor league performance as a projection for major league performance. Hernandez put together an abysmal .244/.276/.312 season at the plate for Bowie and Norfolk in 2007. Even if he experienced no drop off at all in offensive production after a move to the majors, no amount of defensive acumen, even relative to the worst defending SS in the majors (not Tejada), would make up for a .588 OPS.

Baseball Prospectus' Rate stat marks Hernandez as a +9 above average defender and Tejada as a -8 defender. Keep in mind the sample size issues present not only for Hernandez but Tejada as well. There is some inherent error in these numbers for a variety of reasons, but it confirms the notion that Hernandez has been better - much better - defensively than Tejada in 2007.

Let's look at this in terms of winning games. To this end, we'll use WARP as an indicator of a player's contribution towards winning. It's far from a perfect metric, but it can give us a rough idea of the relative value of a player.

Hernandez has accumulated 0.3 WARP in 120 innings of play this year. Projecting that out to 150 full games (about 1350 innings), we can estimate that Hernandez is roughly 3.4 win player. That's not great, but it's certainly a healthy contribution you'd expect from an average player like Melvin Mora or Kevin Millar.

Tejada has played 1002.7 innings this season and totaled 3.5 WARP. Projecting that figure over 150 full games, we see that Tejada projects to about 4.7 WARP for a full season. That means that moving Tejada from SS in favor of Hernandez results in a net loss of about one win over the course of the season, probably a bit more.

But there's a fallacy here. As we project these numbers out to a full season and to next season, we assume that Hernandez can repeat his current .705 major league OPS. We assume that Miguel Tejada will not improve on his .801 OPS, his worst since 1999. And finally we assume that Tejada won't even approach the defensive prowess he exhibited in his first three seasons as an Oriole when he ranged from a +2 to a +14 defender.

If Hernandez regresses back to his minor league offensive numbers, which he almost certainly will, we see an even bigger gap between him and Tejada. If Tejada manages to play midway between where he was in 2006 (when he had an 8.2 WARP) and where he has so far this season, the gap widens still more. What might only be a one win gap under the assumptions that each of the two is playing to their true talent level can easily expand to a four win gap.

There are other considerations. Moving Tejada to 3B is an offensive upgrade over Melvin Mora, although Mora is rated as a +4 defender there this season and it isn't clear that Tejada would field that well after moving to a new position. On the whole, Tejada is a likely upgrade over Mora while Mora would be an upgrade over Jay Payton and Jay Gibbons, assuming he were to be moved to LF.

It would seem that these moves have the chance to be a net zero in terms of wins, although that seems close to a best case scenario. It is quite probable that playing Luis Hernandez as the everyday SS results in a loss of wins. In either scenario, the team is losing several wins on the table by moving Tejada off of SS that must be recouped elsewhere. And at 65-87, it should be quite clear that upgrades must be made. Simply breaking even is not a viable option at all.

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