Jayson Werth turns twenty-nine in three days. If only he’d been a December baby.

At late-twenty-eight, Werth is having himself a career year. He’s slugging .576 with nine HR, twenty-six RBI, and thirty-four hits in thirty-four games. His OPS is up to .932, and his K:BB is a decent 25:12.

But look deeper and the lily shows through the gilt. An OBP of .356 is down .048 points from ’07’s campaign. Jayson’s power numbers are way up, his K totals are right where they should be, but he’s not getting on base at quite the same pace as ‘07. Everything that he hits seems to end up fifteen rows back in RF. What does that mean? Well, it means that he’s been lucky; it means that but for a three-home-run game last night, we’d probably still be talking about Werth as an excellent right-handed platoon OF; not as a potential breakout #3 fantasy OF.

I actually like Werth; I always have. I liked him when he played RF for the Blue Jays, and I liked him when he played RF for the Dodgers. He’s hit .290 against lefties over his career, and his .380 OBP vs. west-facers means he’s a great fourth OF. But his .250 line against righties has always been a problem. In 331 at-bats against left-handed pitchers, Werth’s hit nineteen home runs; in 763 at-bats against right-handed pitchers, Werth’s hit 23 home runs. His K totals against RHP vs. LHP are the real problem: 242 Ks vs. RHP; 88 vs. LHP. That’s one strike out for every three at-bats against righties; one for every four-and-a-half against lefties.

But here’s the thing: How many LHP are in the NL? This year Werth’s got fifty-three at-bats against lefties and sixty-five against righties. He’s hitting .321 against the former vs. .262 against the latter (six HR against LHP vs. 3 against RHP). So he’s spiked one half of his split, but the other’s right where it should be. That average has to come down. It has to.

Werth’s on pace to notch 200 at-bats against LHP this year. In the five years leading up to ‘08 (excluding ‘06, which Werth sat out with a wrist injury), Jayson could claim 278 career at-bats against LHP. This year he’s on pace for 200. OK, by all means, if he’s going to face lefties half the time, then a breakout is almost guaranteed. But is that possible? I don’t think so. But there’s no way of knowing, right? Maybe Manny Parra’ll throw every time the Phillies play the Brewers; maybe it’s all Jorge De La Rosa from here. History, though, says otherwise.

The other problem–if you’re looking for problems–is that Werth has never totalled more than 337 at-bats in a season; aside from ‘05 he’s never had more than 290. Now he’s playing every day. And he’s big and lanky. Again, you can’t predict injuries. But the guy’s playing CF now, and he’s basically on pace to set career highs in every statistical category–MLB at-bats included. (Plus it looks like he’s going to smoke his SB high of eleven in ‘05.) The fact that he saw the DL on an annual basis from ‘02-thru-’06 shouldn’t be ignored. At 6′5″, 210, he sure as hell wasn’t born to play up the middle.

A good season from Jayson would be .280/20/75. It’d be foolish to expect more. He slugged .428 over his minor league career, and, even in his best AAA season (2002) didn’t top eighteen home runs. (Granted, he only had 443 at-bats that year, but seventy-nine home runs in 2,524 minor league at-bats means that he’s miles ahead of his career pace. His MLB totals before last night: thirty-nine bombs in 1,083 at-bats.)

Like him, but don’t love him.