For the first dozen games of the season, we know to be wary of statistics.Anyone can hit .400 in a week, and it’s just as easy to go a miserable 4-for-24. As we enter May, though, we begin to wonder whether these hot starts are actually the beginnings of breakout seasons. In most cases, it’s still too early to say, but by exploring the numbers it’s possible to dismiss some of 2006’s great starts. Here’s a closer look at the hot starts of a young pitcher and a young hitter.

BRIAN BANNISTER
STARTING PITCHER, NEW YORK METS

This 25-year-old right-hander, who should return from the DL next week, may be getting his first taste of the majors, but he certainly looks like an old pro. In five starts so far this year, he’s 2-0 with a 2.89 ERA.

The Mets hurler is the son of Floyd Bannister, the 1976 no. 1 overall draft pick who had a long and mostly unspectacular career as a pitcher for the Astros, Mariners, and White Sox. The younger Bannister was drafted in the seventh round of the 2003 draft and spent the last few years as a Mets prospect of semi-prominence.

Bannister has always thrown hard and maintained decent control, but he never seemed to really dominate minor league hitters. After some success in Double-A last year, he rose as high as no. 9 on Baseball America’s pre-season ranking of Mets prospects, but even they noted that his future was as a fourth or fifth starter at best.

So the question is, can Bannister maintain his microscopic ERA? It would seem pretty unlikely. He’s got a lot going for him, like a stinginess for walks and home runs, but his peripheral statistics in the major leagues are too iffy to believe that his ERA is for real.

The primary thing to note here is that ERA is often influenced by context, and peripheral statistics are always a better predictor of a player’s future. Here, Bannister shows himself to be quite mediocre. He’s accumulated only 14 strikeouts in 28 innings (versus 17 walks), which tells us that the right-hander is depending heavily on his defense and his miniscule home run rate to prevent opposing rallies.

The home runs he might be able to control, but considerable research suggests that pitchers don’t have as much control as we once thought on the batting average of balls they allow to be put into play. Bannister is currently sporting a freakishly low .230 BABIP (Batting Average on Balls in Play), which we can partly chalk up to luck. In the future, opposing hitters will stop hitting the ball right at Mets’ defenders, and when that happens their outs will become hits and Bannister’s ERA will rise.

The kid has looked sharp at times, but he’s not this good. Since 1985, only four pitchers have notched more walks than strikeouts in more than 100 innings and still maintained a sub 4.00 ERA. With these peripheral numbers, Bannister’s ERA is going to jump.Will the Mets survive the learning curve?

NICK SWISHER
LEFT FIELD, OAKLAND ATHLETICS

Swisher was a solid if unspectacular player in his first full season last year,but so far this season he has positively exploded. His current .321 AVG/.408 OBA/.738 SLG batting line in 98 plate appearances makes Swisher one of the most productive hitters of the young season.Is this a sophomore season breakout or another sample-size problem?

One way to tell is to look back at Swisher’s previous years. The young switch-hitter was drafted in 2002 and signed quickly, which means he already has four years of professional experience. Based on those numbers, we can say there’s absolutely nothing about his record to make us believe he is this deadly with the stick.

In his entire pro career, Swisher has never shown the ability to maintain a superior batting average. Last year in the majors he hit .236.In Triple-A in 2004,he mustered a decent .269, but the year before that he was hitting only .230 in Double-A. Now he’s swatting a Tony Gwynnesque .321.What gives?

Batting average, like ERA, is a notoriously fluky statistic. Of all the traditional hitting stats, it shows the least consistency for individual hitters from year to year,which means there is a great deal of luck involved even in a full-season batting average. Essentially, Swisher is seeing the balls he puts in play fall for hits.

What about Swisher’s power? In his best year, he smacked 31 homers; this year he’s already gone yard 10 times,putting him on pace to hit about 65 homers if he plays a full season. Is this luck, too?

It’s probably due to the competition. Though the A’s have been hitting against some decent pitching staffs,the majority of Swisher’s home runs have come against pitchers with noted gopherball tendencies – guys like C.J. Wilson, Jeff Weaver, and Vicente Padilla. In any month of the season, a hitter might face a slate of All-Stars, or he might face guys who struggle to keep the ball in the park. Swisher certainly has a power stroke, but this year he’s been facing guys who pitch like they own stock in Rawlings. He’ll be lucky to get to 40 homers.

This early in the season, the schedule can play tricks on stats, and it’s important to consider every detail. Anyone can have a hot month, and focusing on a player’s batting average, home runs, or ERA is a sure way to be misled.

Mr. Gorman is a writer for Baseball Prospectus. For more state-of-the-art commentary, visit baseballprospectus.com.