Your 2018 Giants: Stratton Status Check

I've been writing about how Stratton is going to be a key starter for the Giants this season, of putting us back to the golden era of starters we had early on, and he has not disappointed so far, with a 2.32 ERA, which is close to his 2.42 ERA in his last 9 starts of 2017.  But there is a lot of noise in the data for both 2017 and 2018 because of SSS, and it probably still exists to a great extent if we just cover those 15 games started, but since I started the data collection, I thought I would finish up this thought.  As always, thank you to Baseball-Reference.com for their data, I would not be able to do any of my work without their wonderful database.

ogc thoughts

Stabilization for key pitching stats occur at around one season's worth of data, research by Russell Carleton of Baseball Prospectus has shown.  Stats like batting average, on-base percentage, slugging (and thus OPS too), isolated power, line-drive rate.  Some do stabilize early, after about 3 regular starts, like strikeout-rate, ground-ball rate, fly-ball rate.  Walk rate stabilizes at around 7 regular starts.

So I looked into the data for 2017's stretch of starts at the end of the season, when he was a regular starter and for 2018.  While some stats have enough evidence, batting line stats are only about half way there, he will need to reach the grind of August to have enough to stabilize those.  Still, lets see how he's doing so far.

2017 Analysis

First big anomaly was his FIP.  He had a great 2.42 ERA, but only a 3.79 FIP, which is still pretty good, just not top of rotation good, as his ERA would suggest.  However, he was hurt by a high BABIP of .317, when the mean is .300 (of course, this could just mean that he's bad at preventing hits, as well, but that's too early to say).   He pitched really well, as shown by his average Game Score of 55 (in games with game score of 55, the team usually wins 61% of the time).  And he had a great 8.7 K/9 and okay 2.15 K/BB ratio.

2018 Analysis

The big anomaly this time is his BABIP, which at .224, is not sustainable, and thus his ERA is also not sustainable.  Still, his FIP of 2.65 is not far from his ERA of 2.32, so that suggests that while some regression is likely, it is not a huge regression.  Still, only 5 games so he will need to keep chugging along.  His K/9 fell to 7.0 K/9 but still has an okay 2.40 K/BB ratio (ideally, he gets it over 2.5).  His average Game Score has been 61, which is excellent (in games with game score of 61, the team usually wins 62% of the time).

Since Stratton Joined Rotation

Overall, he has a 2.38 ERA and 3.32 FIP, both good to great.  Hitters have batted .225/.302/.331/.633 against him, which at a .279 BABIP, he's basically balanced out between the two seasons, and thus there is nothing much to regress against with regards his BABIP, perhaps a slight uptick.

He's just been that good.  He has a good 8.0 K/9 and okay 2.23 K/BB ratio, and both have enough batters faced to say that this is his talent level, so far.  His HR/9 is a low 0.5 overall, which seems too little because he has been mostly a flyball pitcher (ground-ball ratio is much below 1.0 in both seasons), plus his pop-up percentage has not been very high, like it was for Cain or Zito, he's at around 5%.  His overall Game Score is 57 (in games with game score of 57, the team usually wins 64% of the time; oddity of this being higher than above is probably due to fact that this is only from 2007 starts).

PQS and newPQS

I took a look at both PQS and newPQS.  For PQS, in 14 starts (there was a start of 0.1 which would rate a zero, but it was because of a rain delay, so I didn't include it), Stratton had 50% DOM/21%DIS (29%DEC or decent, which I used to call MID).  And for newPQS he had 29%DOM/21%DIS (50% DEC).  So by the PQS methodology, Stratton was a good but not great pitcher, which is what I would say he is right now (which newPQS also seems to say, very decent, but DOM is greater than DIS, so he is leaning good;  as I noted before, a pitcher wants to minimize his disaster starts, as that affects his ERA greatly).


Stratton Status

Overall, Stratton has continued his strong stint at the end of 2017, into 2018.  Combined, his run has looked very repeatable, with a .290 BABIP, 50% DOM per PQS.  In fact, Stratton has upped his rate some, as he was 44% DOM last season (while a rotation regular) and currently at 60% DOM (albeit SSS of only 5 starts).  If he can continue at 60% DOM (and no DIS starts so far, which is even more important), that would be great pitching on his part, and indicative of the elite status of his pitches and the spin rate thereof.  But for now, at best, can say that he's been good but not necessarily great.

Of course, Stratton needs to continue to do this.  But so far he has done it in short stints as a regular starter late 2017 and early 2018, so that is a good sign that he's the real deal.  Looking at when stats start to stabilize, he's about half way towards collecting enough batters with AB's for the batting line to stabilize.   And he looks great so far.

Return to Golden Era

If he can continue this, that would give us three to four starters (once Bumgarner returns) who could toss out a DOM start more times than not:  Bumgarner, Cueto, Samardzija, Stratton.  That was the basis of the success of the Giants rotation from 2009-2013, having 3-4 starters who could toss a DOM start every turn of the rotation, with one of them serving the Zito role, the average-ish pitcher who provides value to the rotation by being a starter you can reliably count on to pitch a full season (innings eater) in a decent way (i.e. an average pitcher or better).  Blach or Holland would then fill the fifth starter role.

As I documented previously, during the golden years for the rotation, we had at least 3 starters who were great starters with at least 60% DOM, 1 starter who filled the Zito role and 1 starting rotation spot that ended up rotating among some good and not so good starters.  Even with that 5th starter, which basically every team has at least one of, the Giants had Top 3-5 standing in the majors/NL during that period.

In a Bumgarner, Cueto, Samardzija, Stratton rotation (with the various  5th starters, Blach, Holland, Beede, Suarez, etc.), if Stratton continues to be successful in continuing his great stretch of pitching, Samardzija would fill the Zito role, given his up and down results, with the potential that if the Shark figures things out, we could have a rotation like we did when we had Lincecum, Cain, Bumgarner, Vogelsong as the great rotation we had in 2011.   Stratton, so far in his 12 starts (the 13th start was rain shortened), has given up 3 runs or less in each start, 2 runs or less in 7 of those 12 starts, which is great for a starter, making him well on the way to claiming a key spot in the starting rotation.