He looked lights out for the first two months of the season, and thrilled us with his triple-digit radar gun readings. But lately, Bobby Parnell has been ineffective — what’s wrong?

As is often the case, there is no one clear-cut answer. But I do have a multi-pronged theory.

Bullpen Routine

The most obvious issue is that Bobby Parnell has never been in the bullpen in the pros before, so he’s not used to the reliever’s routine — mentally nor physically. Since joining the Mets organization in 2005, Parnell has been a starting pitcher, throwing in a game once every five days (with a pitch count) and adhering to a strict program in between starts.

Now, he is expected to be ready every day, which is vastly different in regard to both physical and mental preparation. It’s not unlike going from being a marathon runner to a sprinter. Consider this: through the first 67 games of 2009, Parnell has appeared in 36 ballgames. Last year, while jumping from AA to AAA to the MLB, he appeared in 37 games ALL SEASON. In 2007, Parnell pitched in a total of 29 games, all as a starter. It’s safe to suggest that part of Parnell’s problem right now is being unaccustomed to the daily rigors of a big league relief pitcher.

Secondary Pitch

The next issue affecting Parnell’s performance is his lack of a legitimate secondary pitch. His slider has potential, but is inconsistent, cannot be thrown for a strike, and is 10-15 MPH slower than his fastball. The difference in speed is a problem because it gives batters time to realize what’s coming, and they can lay off of it. Further, batters can wait for a fastball and tee off on it, especially after Parnell misses with the slider once or twice in row. It’s pretty easy for a Major Leaguer to hit the ball hard if he knows what’s coming.

Location and Movement

When Bobby Parnell was developing as a starting pitcher, he relied on a sinking fastball thrown to specific locations in the strike zone. I don’t know for sure, but I’m going to guess he used a two-seam grip, which provides the sink and some lateral movement. Generally speaking, a two-seam fastball has more movement, but a little less velocity than a four-seam fastball. I’m going to make another guess, which is that Parnell is hitting the high-90s and 100 MPH using a four-seam grip, which usually offers much less lateral movement and no sink at all (it’s why infielders and outfielders use a four-seam grip — so their throws are accurate and “true” / go in a straight line toward the intended target).

I’m going to go one more step with my theory, and say that Parnell throws his two-seam / sinking fastball to a specific location, but rears back and throws his four-seamer in the general direction of home plate. As a result, the four-seamer has lots of velocity, but is staying too “true” and is too close to the center of the plate. Hitters may have a hard time getting their bat on a 98-100 MPH fastball even if it’s over the heart of the plate, but eventually, an MLBer will catch up to it — and they are. Add in the previous point about the batter knowing what’s coming, and it’s no surprise that Parnell is getting lit up lately.

The Solution

It’s difficult if not impossible to develop a consistent offspeed / breaking pitch at the MLB level — just ask Mike Pelfrey, who has been developing secondary pitches “on the job” for the past three years. So although one solution is for Parnell to “learn another pitch”, that’s easier said than done.

The second possibility is for Parnell to go back to using his two-seamer more often, to set up the triple-digit heater. But here’s the problem: one of the reasons Parnell was not progressing quickly enough as a starter was his inability to spot his fastball consistently. He is throwing the two-seamer/sinker on occasion here in the bigs, but it “runs” (moves laterally) a bit too much, veering out of the strike zone. Additionally, it’s “only” about 91-93 MPH, so if it doesn’t sink or run, it’s really easy to hit.

Bottom line is this: Bobby Parnell is, right now, a AA starter who needs more time to develop command of his fastball and an offspeed pitch. But, because the Mets were so excited at his velocity, they rushed him to the big league bullpen. After a bit of success, there are now much bigger expectations of him as a future setup man and possibly a closer.

One may wonder why the Mets were so eager to put Parnell’s electric arm in the bullpen, when they already had Brian Stokes. Stokes also throws a straight 96-97 MPH fastball, but he can mix in three secondary pitches (they’re mediocre at best, but they’re better than what Parnell has in his limited repertoire). Could it be part of the organization’s initiative to prove everyone wrong who criticized their farm system? Did they throw Parnell into the fire before he was ready simply to prove their player development is better than what the scouting reports state? A similar move to anointing Dan Murphy the everyday left fielder on the second day of spring training? We can only wonder.

Whatever the case, the point is, the Bobby Parnell experiment should be put on hold. The kid needs to go down to AAA or AA and hone his craft. When he develops either better location of his fastballs, or a legit secondary pitch, he’ll undoubtedly be a lights-out reliever again, with a bright future. Otherwise, expect more of what you’ve seen the past two weeks, while Parnell learns on the job.

(Hat tip to loyal MetsToday reader “sincekindergarten” who wrote an email to me inspiring this post)