For those who just joined us, John Dewan runs the fielding side of Bill James' website. (Dewan has long been one of the most noted sabermetricians quite aside from his current shtuff at BJOL.) His latest article is on Jerry Dipoto's deals this offseason.
Dewan points out that Dipoto's winter trades now total 11, and that these have turned over half the M's starting lineup, 4 out of 8 positions. True, you could say it's 4 out of 9, counting Boomstick at DH, but then again I could say that it's 5 out of 10, counting both the first base players. ...
Dewan's defensive system, which is my own favorite, projects this for the M's 4 new starters:
1) Jarrod Dyson +20 runs above average, replacing Nori Aoki who was -4 runs below average
2) Mitch Haniger +4 runs above average, in place of Seth Smith who Dewan had at -5 runs below league average
3) Shortstop +0 compared to +0 last year. Quite a coinky-dink
4) First base, look out below: Valencia and Vogelbach -15 next year, compared to Lind and Lee at -5 total last season
5) Leading to a grand total of +23 runs saved defensively. Which would be equivalent to a 0.14 bonus to the Mariners' ERA. 0.14 isn't shabby; it's the difference between a 7-8 finish for a team in league ERA, vs. a #10-11 finish or a #4-5 finish
Point is well taken, that the M's will give some glove runs back at first. Dan Vogelbach was #35 out of 35 first basemen last year -- AAA first basemen. LOL. Danny Valencia will also be a fish on a hot concrete dock playing 1B, at least compared to Adam Lind. But! I'd be amazed if the lousiness at 1B completely canceled out the Smith/Cruz to Haniger upgrade, wouldn't you?
I'd have to think that Jerry Dipoto would be disappointed by a 23-run difference next year, teamwide. I'll bet you shekels to shrooms that the M's internal metrics had Seth Smith (and other RF's) at -15 runs or something, and that Dipoto expects better than 4 runs' difference between Mitch Haniger and last year's right fielders.
Dewan does see a 14 (!) runs' difference between Carlos Ruiz (above average defensively) and Chris Iannetta (-10 runs defensively). The backup catcher won't get as many games, but Zunino is young and quick behind the plate and he takes the games Ruiz doesn't. So Dewan's got the M's defense for almost 40 runs including the backup catchers, more like 50 if you like Haniger ...
By the way, Dewan had Jarrod Dyson for 9 runs saved in CF last year, 5 more in LF, and 5 in RF. This in 299 at bats! Dude, if you wanted a defensive specialist, well.
If you want to go crazy against the +40 to +50 runs number, you can count up the blessings from the #4-5 outfielders ... you could muck around with Leonys Martin's injuries last year ... y mooks can think of other factors I'm sure, such as Drew Smyly's fly balls and the Safeco outfield.
The Angels were #11 in the league in runs given up last year, with 727. The Red Sox were #3, with 694, a year's difference being 33 defensive runs between lousy and excellent "Run Prevention Models."