He has a 5.61 ERA in 24 starts this season for Boston, and he was pretty bad in 4 starts for Boston in August, 8.31 ERA, and his ERA since the ASG is 7.82. Not pretty any way you look at it, based on what he did for Boston.
Bad Luck Season
However, it looks much better from a PQS perspective. Since the ASG, in 7 starts, he has 3 DOM starts and 2 DIS starts. That is pretty good in terms of DOM, horrible for DIS, but still shows signs that he is still a pretty good pitcher in certain circumstances. For the season overall, he had 5 DOM and 3 DIS in 17 starts, for an overall 8 DOM, 5 DIS in 24 starts. That DOM%/DIS% combo typically had a 4.70 ERA, which is not good for him but excellent for a 5th starter.
That disparity could be because of where he was. Getting out of the power AL East is good - he has a horrible ERA in Boston, Tampa Bay, Toronto. That plus the DH contributed to his poor ERA overall this season. Plus he has had a great ERA in AT&T Park, Dodger Stadium, Coors, and Chase Field (unusually, he has a bad ERA in PetCo). He also has nice ERA in Citizens Bank Park, the Phillies park, where he would first pitch for us, and in LA where he would next pitch for us.
It also appears that he suffered a lot of bad luck on the road, as both his home and road ERA are horrible, but on the road in 60.2 IP, he has 49 K/18 BB, but 12 HR and 75 hits for a BABIP of .326 on the road. That is a 7.3 K/9, 2.7 BB/9, 2.72 K/BB and bad luck of a BABIP over .300 and a 1.8 HR/9 that suggests that it is far beyond the 10% HR/FB ratio that pitchers regress to and which should drop in half over time. I am ignoring his Boston numbers because the odd ballpark dimensions sometimes either screw with the head of the pitcher or causes a pitcher to pitch differently than he had previously.
Looking Forward: 5th Starter Opponents
The Giants have already announced that they are not skipping the 5th starter's position because of Lincecum's 128 pitch outing in his last start. Assuming they don't skip any of Penny's spots, he is scheduled to pitch for us in Philadelphia (career 2.77 ERA in 2 starts), in LA (3.75 ERA in 66 starts), in SF vs. Cubs then against Arizona (3.88 ERA in 10 starts; career against Cubs 2.64 ERA, against D-backs 2.13 ERA).
With such a good history behind him, it looks positive for him doing well for us, particularly since he is only 31 yars old and should have a few more good years in him, plus the reasons detailed above. Of course, pitchers regress at all ages, so perhaps it was just Penny's time, as he wasn't that good last season either, but it should be noted that he missed half the season with some sort of injury: perhaps that injury was causing him problems last year, whereas this year, with a pretty good DOM% and DIS%, it suggests that this season has been not a regression of skills but a bad luck circumstance with regards to Boston, the AL, BABIP, and the HR ball on the road.
Looks like no matter which side this Penny lands when flipped, the Giants should win. If he is as bad as he was in Boston, then he would be no worse than what we were getting from Sadowski and Martinez and probably still an improvement if we can get some DOM performances mixed in. If he is as good as his career suggests, and as his PQS suggests he could be, then we could have a rotation full of ace pitchers across the board and should start to pull away from the pack by the time we next meet the D-Rox, heck, perhaps sooner, by the start our most important 9 game series of the season, playing 6 with the D-gers and 3 with the D-Rox.
Not Skipping 5th Starter Makes Sense
As noted above, the Giants announced that they are not skipping the 5th starter's spot in order to give Lincecum an extra day of rest, since he threw 128 pitches in his last start. Besides the fact that you don't want to skip over Penny without insulting him (and I just realized that he is now eligible for our playoff roster should we make it), it makes sense to do that. The way the rotation is lining up, we would have Lincecum, Zito, and Cain facing Colorado if we keep the 5th starter through the next two off-days. We should want to throw our best against the D-Rox, and we would if we don't skip the 5th starter for any of the upcoming off days.
Rotation Full of Aces
I hope Penny can revert to his former goodness, not only because that would be good for the Giants, but because it would be an example of what I've been preaching in my blog the past few years about how much of an advantage it can be when you have a pitching rotation full of aces.
When you have one like that, there won't be as many blowouts because there won't be as many DIS starts, which means the team will be in almost every game they play. Plus you won't get into too many bad losing streaks because a DOM start should be coming around the corner any day. And long winning streaks will be more the norm because of the gaunlet that each opposing team faces when they play us, there is no fun and easy starter in the series, each and every game will be a grind, wearing down the other team, game by game.
It also means that the team don't have to be an offensive powerhouse for us to win. And the team hasn't been this season, and even though we have had only 2-3 pitchers doing well at the same time during most of the season, we were able to be among the top teams in the NL for much of the season. Once we got Zito and Sanchez doing as well or even better than Lincecum and Cain, we have been winning more games, finally breaking .500 in August despite no particular hot hitter (We won in June because of Panda's HR hitting).
Adding Penny would eliminate our last weakness in the rotation, hopefully, and give us a chance each and every game we play in for the rest of the season, more often than not. As I will show in my PQS analysis for August, we had a superlative month with our pitching staff, outside of Martinez. With an effective Penny, plus hopefully Molina and Freddy Sanchez for the whole month of September, the Giants can at least win the Wild Card race, and perhaps contend for the title if the D-gers could have a losing month in September.