Evaluating the Trades
It's been about three weeks since the Red Sox traded Nomar Garciaparra away for Orlando Cabrera and Doug Mientkiewicz. Lets take a look at the early impact. The Sox have gone 11-6 in August, with improvements on both sides of the ball.
Sox Batting:
Year to date: 281 BA / 360 OBP / 468 SLG (5.71 runs/game)
August: 290 / 372 / 476 (6.24 runs/game)
Minky has been stinky (243/282/324), and Cabrera has been only fair-a (212/243/333) with the bat. Manny hasn't hit all that well, either, but Ortiz has hit like he has all year, and Millar (375/484/604), Mueller (365/468/538) and Varitek (422/500/756) have been on fire, carrying the club. The offense hasn't suffered for the lack of Nomar's bat - but they'd easily be putting up even bigger numbers if he were in the lineup. Note that the increase in OBP and SLG is all related to batting average. Despite the modest increase in BA, scoring has gone up by half a run per game (this despite "Wave 'em In" Dale Sveum). Why is that? Small ball? "Productive outs"? More timely hitting? It's not a "small ball" stat line, and the Sox are last in "Productive Out Percentage" so I'm going to go with more timely hitting as the reason.
(Oh, and I'm using "Year to date" instead of "April - June" only to save time. It's still an illustrative comparison.)
Sox Pitching:
Year to date: 4.14 ERA, 1.31 WHIP, 6.95 K/9, 2.47 K/BB, .258 BAA, 4.81 RA
August: 4.20 ERA, 1.13 WHIP, 6.96 K/9, 4.00 K/BB, .245 BAA, 4.50 RA
There's your improved defense right there. The Sox have allowed 0.30 unearned runs per game in August, compared to 0.67 year to date. The opponents batting average has gone down some, but the pitching is allowing one less walk per game, too, which has helped the cause (and accounts for over half of the WHIP improvement). Lowe has displayed better control, and Pedro has had three terrific starts out of four this month. On the other hand, Wakefield and Schilling have had some tough outings, while Arroyo continues to have tough luck. Keith Foulke has rebounded nicely from a so-so July, but setup men Mike Timlin and Alan Embree have struggled. Ramiro Mendoza, surprisingly, has been one of the better bullpen arms this month.
So the Sox are scoring 0.5 more runs per game, which can't be attributed at all to the trade, while they are allowing 0.3 fewer runs per game, which is partially a result of the improved defense.
The fielding stats aren't all that cut-and-dried, though. Going position-by-position:
First Base: Minky has been far superior to everybody else, including McCarty. Minky has a Zone Rating of .862 vs. McCarty's .800 and Millar's .770 (the team overall is .791). That means that out of every 100 balls hit in the first base "zone", Minky gets to six more than McCarty and 9 more than Millar, and he's made no errors thus far. That said, if there are as many as four balls hit to first base per game (which I think is a high number), that's 7 extra plays per 25 games, or one every 7.5 games. That's not going to account for a ton of runs.
Second Base: Bill Mueller has been at second for most of the month, and his fielding percentage, range factor and zone rating are far below Mark Bellhorn's, to say nothing of Pokey Reese' (though Mueller has more innings at second than Reese this season already). The downgrade at second (ZR of .739 vs. .821 for Bellhorn) easily fully offsets the improvement at first. This is, however, unrelated to the trade.
Third Base: Kevin Youkilis has better across-the-board numbers than does Mueller at third base, so (until he got hurt), having him in there every day was an improvement at the hot corner (this surprises me, too). But, this is also unrelated to the trade, and you're only talking about three chances per game anyway.
Shortstop: Cabrera is killing Nomar in Zone Rating: .828 to .694. That's huge. That said, more of the games prior to the trade were played by Pokey than Nomar, and Pokey's numbers are much better than Cabrera's. Cabrera has been on par with the "average" Sox shortstop this year.
Outfield: Not much impact. Manny and Damon have been in the lineup all year. Manny missed a handful of games, so the Sox had a few more innings of Millar, Kaplar and Roberts in the OF - all of whom are an improvement over Manny. (Despite the common perception early in the year that Manny is fielding better, the stats no longer bear this out. He's got the worst RF and ZR of his career so far this year.) Damon is also having a subpar year for himself, though I don't know if he's improved any since the trade deadline. My perception is that he's been as good as usual this month, with just the occasional lapse, no different from the rest of the season. Dave Roberts has played a handful of games in RF, and he's good, but that means less Kaplar. Gabe Kaplar has been the Red Sox best glove in the outfield this year. His increased playing time seems to have more to do with his production with the bat and the few games that Manny missed, but I would say that his presence in the lineup has a lot to do with the defensive improvement, too.
So the defense has improved in the corner infield and corner outfield positions, but the middle infield defense is not improved from the "average" Sox lineup this year since the trade, other than the fact that Cabrera is an improvement from his immediate predecessor at shortstop. Again, based on the statistical evidence, it appears that the timing of the plays (or misplays), and the pitchers' performance after errors, also bears much of the credit for the improvement in the Unearned Runs category.
I have to conclude that the big trade has had little real impact in the on-field performance, inasmuch as the new guys haven't done a lot physically to improve the Red Sox' ability to outscore the opposition. I'll acknowledge that it's possible that moving an unhappy Nomar (or just making any kind of move whatsoever) had a psychological impact on the players, resulting in them relaxing more in pressure situations. If that's the case, that alone is enough to make the trade a success. What matters is the wins and losses, and right now it looks like the Red Sox are finally going to win more than they lose for the rest of the way.