Thoughts on Bobby Jenks
What does the future hold for White Sox reliever Bobby Jenks?
Well, I'd be lying if I said I knew. Past performance does not necessarily predict future results (especially for pitchers), but I'd like to review what we know about Jenks and see where he might be heading in the future.
Jenks was drafted in the fifth round by the Angels in 2000. He had one of the best arms in the draft, but was academically ineligible to pitch high school ball, and was known to scouts from a series of tryouts and camps. Jenks pitched horribly in his pro debut: 7.86 ERA in 53 innings for Butte in the Pioneer League, with a 42/44 K/BB ratio. He showed off a 93-96 MPH fastball and a big-breaking curve, but had poor control and no feel for pitching.
Jenks moved up to Cedar Rapids in the Midwest League in '01 and made progress, dropping his ERA to 5.27 in 21 starts, with a 98/64 K/BB in 99 innings. His fastball increased to a consistent 95-96 MPH, topping out at 98. His curveball improved, and his changeup improved from non-existent to below average. His control was still very shaky, but he was getting better. He was impressive in Texas League playoff action, and some people thought he was positioned for a breakout.
2002 was split between Class A Rancho and Double-A Arkansas. His ERA dropped to 4.70 in 20 starts, with a 122/90 K/BB in 133 innings. His fastball got faster, consistently at 96-97 MPH now, topping out at 102. His curveball and changeup got better. But his control remained unreliable, and Jenks was suspended at one point for immature behavior and violating organization rules.
Jenks made 16 starts for Arkansas in 2003, and he pitched very well indeed: 7-2, 2.17, with a 103/51 K/BB in 83 innings. His velocity dropped a hair, consistently down to "just" 93-95 MPH, although he still bumped up around 100 a few times. His curveball continued to improve, while his changeup settled into the "adequate" range. His control was better, though still below average. Warning signs: continued concern over immature behavior, and, more ominously, a stress fracture in his elbow that cost him two months of playing time.
'04 was a disaster. He was limited to just five games and 19 innings overall, on the shelf with more elbow problems that eventually necessitated surgery. His ERA was over 9.00. His velocity dropped into the lower 90s. The Angels stuck him on waivers, and the White Sox claimed him in December.
As you no doubt know, Jenks has been a revelation this year. He was healthy at the beginning of the season. The Sox converted him to relief, and he picked up 19 saves with a 2.85 ERA in 41 innings (48/20 K/BB) for Double-A Birmingham. His velocity came back, and he took well to the bullpen role, which seems to suit his personality. Promoted at mid-season, he posted six saves for the Sox with a 2.75 ERA in 32 games, 50/15 K/BB in 39 innings. Remarkably, he's shown better control in the major leagues than he ever showed in the minors.
The question comes down to sustainability. In terms of physical potential, what Jenks did this summer is not a fluke. His pure stuff is among the best in the game, and when healthy he has no trouble overpowering the best hitters. His control has improved from dismal at the start of his career, to below average in most of it, to fairly good this year. Will his control continue to improve? Will it stay the same as it is now? Or will it regress?
Frankly, I haven't a clue what Jenks will do. I would like to point out that we have a positive sample of just 80 strong innings this year, compared to erratic and often poor performance in the rest of his career. Do the 80 strong innings, including 39 in the majors, override the rest of his track record? I don't know, and no one else does, either.
Jenks seems to have made legitimate progress in terms of emotional maturity and work ethic, and that helps. I still worry that he may regress in those areas, but he might not. Health-wise, he could blow out his elbow totally, or shred his shoulder. Or he could have a bout of Steve Blass disease. Or he could continue to throw strikes and emerge as a top-notch closer.
I really have no idea. What do you guys think?