How Has Lance Lynn Performed While Replacing Chris Carpenter?

On Monday night, second-year pitcher Lance Lynn made his sixth start for the St. Louis Cardinals and put together another solid outing. The start was the shortest of his 2012 season, lasting only five innings due to inefficiency. The four walks he issued are a season high and a big reason behind Lynn reaching the 91-pitch mark in just five innings. Nonetheless, Lynn managed to hold the Diamondbacks scoreless, allowing only three hits and inducing seven strikeouts. With the help of a dinger binge from his offense and relievers not named J.C. Romero, Lynn was able to notch his league-leading sixth pitching "win."

During spring training Lynn took the place of injured ace Christ Carpenter in the Cardinals starting rotation. It's amazing just how thoroughly Lynn has been able to replace Carp in the season's early going. Lynn has been so good that hardly anyone is clamoring for the Cardinals to sign veteran free agent Roy Oswalt.

After the break, there is a chart comparing Lynn's 2012 to date to Carpenter's 2011.

It is incredible to me that Lynn has posted better numbers over his first six starts than Carpenter in every category but BB/9. It's not surprising that control artist Carpenter walks fewer; rather, it's surprising how excellent Lynn has been in every other category. Whether Lynn can keep it up is a legitimate question, especially when one looks at the stats that are typical indicators of luck.

A .209 BABIP is incredibly low and Lynn's will very likely rise. That being said, we know that pitchers who have a high strikeout rate like Lynn's of 8.61 typically have a lower than average BABIP because they induce weaker contact. Lynn appears to be inducing weaker contact with opposing batters managing just a 17% LD rate against him. For comparison, opposing batters posted a 24% LD rate against Carpenter in 2011. This is likely a big reason why Lynn's tERA this year is 3.01 and Carpenter's 2011 tERA was 3.85.

Perhaps the area most ripe for regression is Lynn's strand rate; or, LOB%. An average LOB% is typically around 75% in a given year. So far in 2012, the league LOB% is 72.9%. Compared to the league average, it's safe to say that Lynn's strand rate of 93.8% is astronomically high and will undoubtedly drop. For some context, only six starters managed a LOB% of 80% or higher last season. Jeff Weaver's 82.6% strand rate was the highest. Lynn's LOB% is going to drop and, when it does, his ERA will rise.

By season's end, when his batted-ball and left-on-base luck evens out, Lynn isn't going to be a sub-2.00 ERA pitcher. He very likely won't be a sub-3.00 ERA pitcher, either. To replace Carpenter's 2011 production, he doesn't need to be. It will be interesting to see if Lynn can keep pace with Carpenter's 2011 as the season progresses and the innings pitched total increases to a level he's never before experienced.