After two years platooning with players who subsequently have bounced around the league having trouble finding jobs, Matt Diaz probably felt a little more comfortable with his job heading into 2008. The right-handed batter had earned a starting spot outright, OPS+ing 114 and 124 in 2006 and 2007 while showing an inconsistent platoon split (he favored lefties in ’06 and righties in ’07).
This year, Diaz is off to a slow start. Entering his 3-for-4 game on Monday, he was hitting .258/.258/.323, showing zero plate discipline (down a notch from “very little” in previous years) and almost no power (down from “moderate”). Last year, he walked 4% of the time and had an isolated power of .161, making him the type of guy you want in your lineup, but only as long as he’s hitting over .300.
The problem with this is that batting average can vary greatly from year to year even without a change in “true talent.” A “true” .300 hitter can hit .270 one year and .330 the next due to random chance. The question is: what is Diaz’ true talent? After consecutive seasons over .327 and with around 300 at-bats, it seemed like Matt was becoming one of the league’s top contact hitters. However, it may be that he’s really a .290-.310 hitter who got lucky two years in a row. His BABIP was .367 and .378 in each year, both high figures even when you consider that he’s a decent line drive hitter. So perhaps some regression was due.
Back to Matt’s slow start: he was hitting .258 with a .333 BABIP entering Monday. A shorthand way of determining whether a hitter is getting “hit lucky” is to add .120 to his line drive rate, which then was .178, to get his BABIP. If actual BABIP (for Diaz, .333) is higher, it’s likely to regress toward that calculated rate (.298). If anything, he was getting a bit “lucky” again. (I’m putting “lucky” in quotes for lack of a better term. I won’t suggest that I can completely separate luck from ability based on these stats.) It’s entirely possible that he has actually struggled more than his current stats indicate.
I focus mainly on Diaz’ batting average because he derives so much of his value from a high batting average. Other players compensate for poor contact hitting with great power or speed, neither of which Matt has. His power is also down, so he’s been struggling across the board.
Having said all of that, Diaz’ performance thus far is based on a very small sample size: three weeks of a season, or 62 plate appearances. It’s too soon to say whether Diaz is regressing, because we just haven’t seen enough of the season to react.
Bobby Cox, on the other hand, has seen enough to warrant spelling Diaz with Gregor Blanco. I’m not especially high on Blanco as a long-term prospect, since he has virtually no power, but he could be a decent on-base guy, and the Braves have recently done much worse with Diaz’ platoon partners. It hurts not to see an OPS over .800 at any stop on his minor-league resume, though.
I certainly don’t think Blanco is a better option than Diaz right now, so I’m still hoping he only gets occasional starts once he inevitably cools off. Over the course of the season, it probably wouldn’t be a bad idea to give him a start a week in place of Diaz and Kotsay, though, especially given the latter’s recent injury history.
Lastly, let’s have a quick look at the Braves’ other outfield options, should both Diaz and Blanco falter this season. Josh Anderson was in the running for the fourth outfielder job in Spring Training, but I don’t think he offers much upside that Gregor Blanco doesn’t have. Let’s hope the Braves steer clear of Joe Borchard. Brandon Jones is hitting .228 with no homers, but he’s the best long-term option. I think Anderson would get the call if the Braves happened to need someone immediately, but Jones has the best chance of making it to Atlanta otherwise.
A few references for you:
Matt Diaz at Baseball Reference
Matt Diaz at The Hardball Times
Matt Diaz at FanGraphs
Gregor Blanco (minors) at Baseball Reference
Gregor Blanco at FanGraphs
jfwiii.net 
Bobby’s insistence on platooning Diaz tends to drive me crazy. Especially towards the end of last season when Willie Harris showed no more ability to hit major league pitching than I could, and forgot how to steal bases besides.
I know that you sabermetrician types aren’t big on BA, which I understand, but at the same time, I have a hard time believing that a guy who hits .338 in 350+ at bats doesn’t at least deserve an extended audition at playing everyday.
I do think that is important to note that in 2006 Matt Diaz started the season hitting .200 in March/April. He finished 2006 with a .327 mark.
In 2007 he started the season hitting .259 in March/April and finished the season at .338.
So far this season (April 22) he is hitting .288. What will he finish with????
So essentially…and perhaps there’s a better way to put this…but it seems as if Bobby is yanking Diaz for having the best April he’s ever had.
It can be frustrating to have a roster where 3-4 of your contributors are slow starters.
I just don’t get it either, and I wonder what would be happening if Gregor Blanco hadn’t gotten off to such a hot start with the bat.
There’s plenty of merit to batting average with respect to Diaz, since contact hitting is far and away his best skill. I think there’s enough in the stats to say Diaz deserves a full-time role. At the very least, he deserves a long leash out there, more so than Kotsay and Escobar, and maybe even Kelly Johnson (and you know Bobby’s not platooning either Escobar or Johnson anytime soon).
You have to wonder if Bobby “playing the hot hand” shakes Diaz’ confidence just a bit. Perhaps one day, before it’s too late, we’ll find out what he can do in a full season of at-bats.
I didn’t notice that Diaz is another slow starter. That makes it even more amazing that the Braves are performing as well as they have been. Perhaps when (if?) Chipper comes back to Earth, everyone else can start picking up the offensive slack. Right now, though, the Braves still have the second-best run differential in the NL, and that’s worth bragging about.