During the 2010 season, I wondered if David Wright was actually any streakier than any other hitter. I know he has a reputation for ups and downs, but I speculated that perhaps all players endure ups and downs and we just notice Wright’s because he’s the best hitter on the Mets and because we’ve labeled him “streaky.”

Today at Beyond the Boxscore, Bill Petti investigates Wright’s “volatility” by calculating and plotting 10-day moving averages for his WPA (win probability added) from 2005 on. It’s an interesting read with colorful graphs, and using the moving averages seems as good a way as any to try to track consistency. He concludes:

As one would expect, Wright experiences peaks and valleys over the course of the season.  If we look closely, however, we see that Wright does appear to have become both more volatile over the past few years and has experienced an increase in stretches where, on average, he negatively affects the Mets chances of winning games.  Wright’s positive streaks do not last as long and his negative streaks have deepened and last longer.

Wright’s best year was 2007, where he averaged a WPA of .029 (highest since 2005) and had a standard deviation of .032 (second lowest since 2005).   Wright’s lack of volatility coincided with his best overall performance at the plate (OPS+ of 149, offensive Wins Above Replacement of 7.5).  Since 2007 we see an increase in deep negative stretches, with 2009 and 2010 looking especially volatile.  Essentially, Wright has gone from a consistent high-performer to a boom-or-bust type player.

OK, a couple issues here: First, it’s really difficult to determine if Wright is any more volatile than any other baseball player without points of comparison. Petti shows that Wright has endured longer and deeper slumps in 2009 and 2010 than he did in 2007 and 2008, but he doesn’t show how Wright’s peaks and valleys in any season compare with those of similar offensive performers.

And more importantly, it seems like mere common sense that Wright would have endured more slumps in 2009 and 2010 than he did in 2007 and 2008: He wasn’t as good. Wright enjoyed the best offensive season of his career in 2007. Of course he didn’t have as many slumps then as he did in 2009.

Wright’s wOBA has been on a steady decline since 2007, so it seems to me to make perfect sense that he’d also seem to be getting progressively “streakier” in that time. If I had to bet, I’d guess a similar analysis of Ryan Howard would determine he was way more volatile from 2008-2010 than he was in 2006 and 2007.

It’s a chicken-and-egg thing, of course, because you can say, “oh well maybe if Wright were less volatile the last two seasons his stats for the season would have been as good as they were in 2007 and 2008.” And that’s true, but it doesn’t really matter much one way or the other. Without other players for comparison, we have no way of knowing if Wright’s perceived streakiness is something unique to him or just normal fluctuation, an expected function of performance at his 2009 and 2010 levels.

My expectation is — as it was in June — that the only very consistent performers in baseball are the truly excellent (like Wright in 2007) and (to reuse a phrase from yesterday) the downright Rafael Belliard awful.

The Mets signed lefty Chris Capuano and righty Taylor Buchholz last night and designated Ryota Igarashi for assignment.

According to Adam Rubin, Capuano contract provides a $1.5 million base salary with incentives. Back in the middle part of the aughts, after his first Tommy John surgery but before his second, Capuano was a stalwart member of the Gary (IN) Templetons’ rotation (also the Brewers’, but my fantasy league was pretty high stakes back then).

In 2005 and 2006, Capuano chewed up innings and struck out a decent number of batters, a nice if unspectacular pitcher. Though he missed all of the 2008 and 2009 campaigns after another arm injury shortened his 2007 season, he returned to the Brewers in June of 2010 and enjoyed a decent stint as a long reliever and spot starter until he took a place in Milwaukee’s rotation in late August.

In those final seven starts of the season, Capuano posted a respectable 4.14 ERA with small-sample peripherals vaguely in line with his 2005 marks. He featured a similar mix of pitches as he did in his healthy years and actually threw his fastball a touch harder. He seems like a great pickup at the cost, and should earn a role in the middle of the Mets’ rotation if he can stay healthy. That’s nothing certain, of course — he has, after all, had two Tommy John surgeries. But if he hadn’t, he wouldn’t be available for $1.5 million.

Perhaps most importantly, Capuano is apparently a Segway enthusiast. In this 2007 interview, he reported that he was frequently called a nerd by passersby while he sped around Milwaukee on his personal transporter. I can’t speak for my fellow New Yorkers, but I can promise Chris Capuano this: If I ever see him riding around Midtown on a Segway, I’ll call him a different name: “Hero.”

(Hero? That could work for me.)

Capuano also appeared on an episode of The Young and the Restless and was Phi Betta Kappa at Duke. Bronx Banter’s Emma Span recently described him as “blogger catnip.”

As for Buchholz, former roommate and Rockies fan Ted Burke called him “the best setup man in the game” in his healthy 2008 campaign, and though my namesake is prone to hyperbole, Buchholz was pretty awesome that season. A converted starter, in his lone healthy year of full-time relief Buchholz posted a 2.17 ERA and a sub-1 WHIP. Those numbers belied his just-pretty-good peripherals, but even just-pretty-good would be a nice addition to the Mets’ bullpen.

Buchholz missed all of 2009 following Tommy John surgery, returned to the Rockies in July of 2010, then promptly returned to the disabled list with lower-back stiffness. He did finish the year with two healthy innings for the Blue Jays in September. At $600,000 — barely above the league minimum — he seems a worthwhile bargain.

Incidentally, both Buchholz and Capuano went to high school in Springfields — Buchholz in Pennsylvania and Capuano in Massachusetts.