Seattle's new regime made defense a priority during the offseason, acquiring elite fly-catchers Franklin Gutierrez and Endy Chavez to team with Ichiro Suzuki for a three-center fielder outfield and the results have predictably been dramatic.
Last season the Mariners ranked 11th among AL teams in runs allowed, but so far this year they've been by far the best team in the entire league at preventing runs while slicing their ERA from 4.73 to 3.59.
Improved pitching has obviously played a big role, but a dramatic change in the quality of the Mariners' outfield defense has been an overlooked component. Or at least it was. Chavez suffered a torn ACL in a collision Friday with Yuniesky Betancourt, knocking him out for the remainder of this season and possibly part of 2010.
Chavez is a corner outfielder who was hitting just .273/.328/.343, so at first glance you might think that his injury would actually help the Mariners, but his glove in left field was a huge asset. In fact, with Chavez, Gutierrez, and Suzuki playing 80 percent of the left field, center field, and right field innings Ultimate Zone Rating ranks the Mariners' outfield as the best in baseball defensively at 22.2 runs above average.
Jarrod Washburn is one of the most extreme fly-ball pitchers in the league, so it's no coincidence that his ERA has improved from 4.67, 4.32, and 4.69 in his first three years in Seattle to 3.29 this season. Washburn hasn't become a new man at the age of 34 and his secondary numbers show him as the same mediocre pitcher, but having three center fielders chasing down everything in the gaps made him look a lot better.
Seattle's outfield defense will still be plenty strong without Chavez, because Gutierrez is an amazing center fielder and Suzuki will probably win his ninth straight Gold Glove in right field, but with Wladimir Balentien now in left field they've gone from spectacular to merely very good amid rumors that Washburn is on the trading block.