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Coming into the 2010 season, Jay Jackson was one of the two best pitching prospects in the organization, and he was also the closest to the major leagues. While Andrew Cashner was starting the season in AA trying to become a starting pitcher, Jackson was in AAA Iowa having already shown he could be a starter. In 24 starts across three levels in 2009, Jackson posted a 2.98 ERA in 127 innings.

2010 was a fairly up and down season for Jackson, which might have taken a little of the shine away, but he’s still on track to be in the Cubs’ starting rotation fairly soon. Jackson made 32 appearances at AAA Iowa this year, 25 starts, and eight bullpen appearances. He finished with a 4.63 ERA in 157.1 innings pitched.

Jackson had been a high strikeout, high walk pitcher before 2010, but this season it seems like he changed. His career strikeout rate is 8.6 per nine innings (and never below 8.4 at any level before this season), but it dipped to just 6.8 K/9 this year. That could be because of an effort to improve his command (we will get to that in a moment), or it could be because AAA hitters are a bit more advanced that what Jackson has faced in the past. Either way, it is a bit concerning, and something to look at next season.

The good news is, Jackson was able to improve on his shaky command, walking just 2.9 batters per nine innings, a nice drop from this 4.2 BB/9 he had in AA last season. While pitchers have succeed in the major leagues with high walk rates like that, it doesn’t happen often, and it is nice to see Jackson improve on his command. Now the question is, can he maintain a lower walk rate and get his strikeout numbers higher.

Jackson gave up more hits per nine innings and home runs per nine innings than his brief career averages. He also allowed almost twice as many earned runs as last season, with just 30 more innings. All of that is concerning for sure, but keep in mind a mid-season role change that clearly affected his season. The Cubs, in their infinite wisdom, moved Jackson to the AAA bullpen in an effort to get him to the big leagues faster, part of the mid-season last ditch effort to stay in the playoff race. While Jackson worked back into starting shape, he had a few rough starts, which is to be expected. At some point the organization will stop changing the roles of their best players mid-season.

Another thing I noticed when looking at Jackson’s numbers, his FIP by inning goes up quite a bit in the fifth inning. His home run rate from the fifth inning on skyrockets, all of which seems to suggest he wears down quickly. Maybe that means he’s better suited for a bullpen role long term, maybe it’s a statistical fluke, maybe he just needs more time as a starter so he can learn to pitch deeper into games. Just another thing to watch for next season.

Jay Jackson is very close to being a major league starting pitcher, despite a bit of a down season. He’s probably the next guy in line to join the starting rotation next season, and either way I would guess he’s starting games at Wrigley Field come August 2011. He’s still very young, next year will be his age 23 season, and he’s already shown he’s capable of amassing plenty of innings and not break down. Hopefully he proves worthy of being in the major leagues next season, and the Cubs give him a chance to start.

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