John Patterson of the Washington Nationals (AP)

Prospect Retrospective: John Patterson

John Patterson was drafted by the Expos in the first round in 1996 (5th overall) out of high school in Orange, Texas. But he was declared a free agent a couple of months after the draft, due to a previously-ignored loophole in the rules that said a team had to offer a contract within 15 days of the draft. The Expos didn't do that, and consequently Patterson was freed from his draft restriction, signing with the Diamondbacks as a free agent.

Patterson spent 1997 pitching for Class A South Bend in the Midwest League. Although he went just 1-9 in 18 starts, he posted a solid 3.23 ERA and a 95/34 K/BB ratio in 78 innings. The K/IP was particularly impressive. For some reason, I didn't give him a letter grade for the 1998 book, but I did note that he was a fine prospect and "could end up at the top of the list" next year. Retrospectively, he would have received at least a Grade B based on his South Bend numbers.

Promoted to the California League for '98, Patterson went 8-7 with a 2.83 ERA and 148/42 K/BB in 127 innings. These are sharp numbers, made more impressive by the fact that he did this at High Desert, a difficult environment for pitchers. I gave him a Grade B+ and rated him as the number 23 prospect in all of baseball. He was clearly an elite prospect, and looked like he would justify Arizona's investment in him.

For '99, Patterson moved up to Double-A El Paso. His ERA spiked to 4.77, but a lot of that was due to park/league context. His K/BB was 117/42 in 100 innings, and he gave up 98 hits. . .his ERA should have been at least a half-run lower based on his component ratios. A trial at Triple-A Tucson (1-5, 7.04 in 6 starts) did not go well, but I still gave him a Grade B+. He slipped one notch on the Top 50 prospects list, going down to 24.

Patterson blew out his elbow early in 2000, requiring Tommy John surgery.

He returned to the mound in 2001, and was ineffective in Triple-A, going 2-7, 5.85 with a poor 40/31 K/BB in 68 innings. His rating dropped to Grade C for obvious reasons. His velocity was back, but his command was quite weak, and given the doubtful component ratios, I dropped his grade to Grade C. I was concerned that he was rushed back too quickly from surgery, and would never become the pitcher he seemed pre-injury.

Patterson pitched in Triple-A in 2002 and was more effective, going 10-5, 4.23 with a 104/45 K/BB in 113 innings, closer to his pre-injury standards. He also pitched well for Arizona down the stretch, going 2-0, 3.23 in 5 starts. I gave him a Grade B in the 2003 book.

Patterson spent 2003 back in Triple-A, pitching well again (10-5, 2.63) but limited to 18 starts by shoulder trouble and mechanical difficulties. His K/BB slipped to 74/43 in 109 innings, not much change in his control, but a substantial drop in his strikeout rate. I remember thinking at the time that he 1) needed a change of scenery and 2) was unlikely to develop into anything more than an average pitcher. The Arizona brass apparently agreed, and he was traded to the Expos in the spring of 2004.

Patterson went 4-7, 5.03 in 19 starts for the Expos last year. But there were hints in his numbers of his old talent, notably a 99/46 K/BB in 98 innings, the once-per-inning strikeout rate being a strong sign. Patterson has been one of the best pitchers in the National League so far in 2005. At age 27, he still has many potentially productive years ahead of him.

When healthy, Patterson's minor league track record was marked by strong K/BB and K/IP ratios, with little deterioration as he moved up. His ratios slipped when his health was a question, but when his arm doesn't hurt, his component numbers have been solid.

Comparable Pitchers to John Patterson, through age 26 (based on Sim Score and PECOTA, active pitchers not included)

Bill Hands
Bob Porterfield
Ray Kolp
Scott Sanders
Don Larsen
Jack Armstrong
Steve McCatty