When the Padres acquired Miguel Tejada, they were likely looking for little more than a stopgap until David Eckstein returned from injury and some added depth for their bench. Instead, they’ve received one of the most productive players since the trading deadline. Tejada had put up a solid (and PETCO deflated) .263/.314/.426 line entering last night’s game. In said game, Tejada once again came up large for San Diego, homering and posting +.240 WPA as part of a 3-4 night.
That slash line above might not look that impressive, but we have to remember that this is PETCO Park we’re talking about here. According to StatCorner, the park suppresses wOBA by about 8% for right handed hitters, a number which is supported by Baseball-Reference’s multi-year park factor.
As Dave mentioned earlier this month, when a park strongly effects the run environment, it inherently changes the value of a run to a team.
That makes each individual run less valuable in helping a team win. If the Rockies need to score six runs at home in order to win, a home run – which has a league average run value of 1.4 runs – by Gonzalez gets them 23.3 percent of the way there. The Padres, for instance, only need to score four runs in order to win at home, so a home run at Petco by Adrian Gonzalez, worth the same 1.4 runs, gets them 35 percent of the way to their needed total. A run in San Diego, or anywhere really, is worth more than a run in Colorado because of the run environment.
That quote is remarkably convenient to our discussion here. Unadjusted, Tejada’s offensive line is just slightly above average. But a team that is playing in PETCO Park and scoring the league average amount of runs per game – like, say, the 2010 Padres – is likely to win a significant amount of games. With the park adjustment, Tejada has a 112 wRC+, equaling his mark last season as well as some of his early years with the Athletics. Throw in that Tejada is doing that at the shortstop position without negatively impacting the team in the field, and he’s a player that’s provided 1.5 WAR in a mere 204 plate appearances with the club. Tejada has played like an All-Star for San Diego down the stretch, and given their precarious and ever-changing position at the top of the National League West race, that makes him one of the most important deadline acquisitions of the season.
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