Although everyone seems to agree that Kansas City Royals starting pitcher Ervin Santana had a rough season pitching last season for the Los Angeles Angels, most people don't realize how unique of a season Santana had last year. Among pitchers who threw enough innings to qualify for the ERA title, Santana's 2012 effort is tied for the third-worst season a pitcher has thrown in the last 20 seasons.
It's difficult to post a negative fWAR value if you qualify for the ERA title. There is value in throwing innings, so you would expect someone who manages to throw at least 162 innings to perform better than a replacement level pitcher, since most pitchers cannot throw that many innings in a season.
You would also expect a team to stop starting a pitcher who is performing so poorly, so he would stop damaging the team. Jonathan Sanchez managed to compile -.7 WAR in only 64.2 innings pitched last season, which is unbelievably awful. The Colorado Rockies shut Sanchez down last season, which is what most teams do when they have a veteran starting pitcher pitching below replacement level.
In some ways, it's impressive that Santana still picked up the ball every fifth day even though he pitched so poorly. According to Fangraphs, only 15 pitchers in the last 20 season have posted a negative WAR value while managing to qualify for the ERA title.
Of course, the Royals are expecting Santana to recover from his 2012 performance and perform much better in 2013. Whether they should expect Santana to pitch that well is a different question. I imagine the Kansas City front office and Santana optimists/apologists would point to his relatively high innings pitched total as some sort of proof that he still has value. The Royals have stated they want their starters to throw 1,000 innings, and Santana would have been fourth on the team in innings for Kansas City last year
ZiPS predicts that Santana will throw enough innings next season to qualify for the ERA title next year, but the projection system has Santana at .6 WAR in 2013. Kansas City is paying Santana $12 million next season, so .6 WAR is not really an acceptable performance.
In all likelihood, Santana will not be worth the money the Royals are paying him in 2013, but if Santana could at least hover around league average as a pitcher next year, I imagine most Kansas City fans would declare the trade a success for Dayton Moore. I decided to look at the other 14 pitchers who posted negative WAR as qualified starters to see if any of them bounced back like the Royals are hoping Santana will.
Most of the high-inning starters who posted negative WAR values did not recover the following season. Only 3 of the other 14 pitchers managed to post a WAR above 1.0 the following season. So even though this group of starters managed to throw a large amount of innings despite the fact that they pitched terribly, it did not indicate that they were more likely to recover from a terrible season than a pitcher who threw less innings.
Still, there are few examples to cling to if you want to hold out hope for Santana in 2013. Todd Van Poppel followed his disastrous 1994 campaign with 1.8 WAR for the Oakland Athletics in 1995. Van Poppel only threw 138.1 innings for Oakland in 95, and he was still 23 years old during his "bounce-back" season. Santana is 30 years old, so it's impossible to blame his 2012 struggles on being an inexperienced pitcher.
Jason Marquis pitched horribly for the St. Louis Cardinals in 2006, posting a -.7 WAR despite throwing 194.2 innings. Marquis went to the Cardinals' rival in 2007, and recovered nicely with 1.7 WAR and 191.2 innings pitched for the Chicago Cubs. Marquis had two more strong seasons in 2008 and 2009, including a career high 4.0 WAR for the Rockies in 09. Santana would not be worth $12 million in value to the Royals at 1.7 WAR, but he would not kill the team with that number either.
If you want to hold out hope that Santana can pitch above-average in 2013, you basically have to pray that he is Bronson Arroyo. Arroyo managed to compile -1.3 WAR in 2011, which is the worst WAR value among all qualified starters in the past 20 season. Similar to Santana, Arroyo suffered from a huge spike in his HR/9, allowing an unfathomable 2.08 home runs per nine innings. Arroyo surrendered 46 home runs in 2011, which is more home runs than a Royal has ever hit in a single season.
Arroyo managed to get his home run numbers under control in 2012 with a 1.16 HR/9, which is much more in line with his career numbers. The difference between Santana and Arroyo, however, is the parks that they pitch in. Arroyo pitches in a bandbox known as Great American Ball Park, which was the second friendliest home run friendly park in 2012. Santana pitched half of his innings in Angel Stadium, which was the sixth hardest park to hit a homer in 2012. Kauffman Stadium was essentially league average at suppressing home runs in 2012. So Santana is moving to a more home-run friendly park while attempting to lower his home run numbers back to an acceptable level.
So while all of us Royals fans want Santana to recover and pitch well in 2013, the safe bet is that he will fail to reach 1.0 wins above replacement next season. Even if Santana is healthy for the entire season (ahem) pitchers who pitch as poorly as he did normally fail to bounce back, regardless if they threw a lot of innings.