The "Quality Start"

by Adam Peterson on Aug 31, 2008 11:50 AM EDT

During Friday's telecast, Dick & Bert discussed the Twins rotation and their consistency in putting up quality starts again and again. Because some national baseball "experts" (Dibble and Kennedy for one, although I love their show) simply don't seem to get it, citing "6 IP / 3 ER is a 4.50 ERA, which isn't very good", I decided to do a little research on the 2008 Twins season and quality starts.

Overall for the season, our starters have made 73 quality starts (QS) in 136 games. That's a 54% clip.

In those 73 QS, we have a record of 50-23 (.685). In the remaining 63 non-QS, we have a record of 26-37 (.413). Pretty large difference, it's a testament to our offense that we've managed to win as many of the non-QS games as we have. I suspect in years past we'd be much worse off.On the other hand, I also suspect our winning percentage in QS is a bit lower than other years due to our suspect bullpen.

We've also been really consistent month by month. Between 52 and 57% each and every month. Improving in August, which is also nice.

April: 14 for 27 (52%)
May: 15 for 28 (54%)
June: 15 for 28 (54%)
July: 13 for 25 (52%)
August: 16 for 28 (57%)

Breaking down the numbers, pitcher by pitcher. Also quite consistent. Blackburn and Baker are the best, but Perkins, Slowey and Liriano are not far behind. A bit surprising that we have such a good record in Baker's non-QS. He gets screwed by 1-0 games when he pitches lights out, but he also gets saved when he stinks. Interesting.

Blackburn: 16 for 27 (59%) - Team is 10-6 in QS, 3-8 in non-QS, 13-14 overall. 
Baker: 13 for 22 (59%) - Team is 6-7 in QS, 7-2 in non-QS, 13-9 overall.
Perkins: 12 for 21 (57%) - Team is 9-3 in QS, 5-4 in non-QS, 14-7 overall.
Slowey: 11 for 22 (50%) - Team is 10-1 in QS, 3-8 in non-QS, 13-9 overall. 
Hernandez: 11 for 23 (48%) - Team is 10-1 in QS, 4-8 in non-QS, 14-9 overall. 
Bonser: 6 for 12 (50%) - Team is 3-3 in QS, 2-4 in non-QS, 5-7 overall. 
Liriano: 4 for 9 (44%) - Team is 2-2 in QS, 2-3 in non-QS, 4-5 overall. 3 for 5 since coming back in August.

Finally, relative to the league, our 73 QS puts us at 7th in the majors, 4th in the AL behind the Angels (79), White Sox (77) and Indians (74). Good company.

Bottom line, we've got a nice rotation here. Consistent, gives us a chance to win game after game. Now if we could only say the same about the offense and bullpen...

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Comments

Maybe I missed this, but

>>In those 73 QS, we have a record of 50-23 (.685).

What are the percentages for the other AL teams in QS?

by Johnny Safron on Aug 31, 2008 9:24 PM EDT reply actions

Not sure

I calculated the Twins’ record by hand using game logs. Would have to go to each team’s site and go game by game. Woudl be interesting if anyone’s done this…

by Adam Peterson on Aug 31, 2008 10:01 PM EDT up reply actions

Damn

Obviously, the suspicion is that the majority, maybe the vast majority, of teams have high winning percentages when their starters go 6. But that game log stuff is too much work. My enthusiasm for the answer has dropped to near zero.

I bet each team tracks this, however.

by Johnny Safron on Aug 31, 2008 11:29 PM EDT reply actions

Found this through Google

>>As Rob Neyer notes in this ESPN Insider article, when Lowe created the stat in 1985, there were 2,155 quality starts in all of baseball, which turned into 1,451 wins (67.3). In 2005, 20 years later, there were 2,447 quality starts translating into 1,650 wins (67.4); nearly identical percentages. Simply put, if a pitcher turns in a quality start, his team is likely to win the game two out of three times…and .667 is a pretty damn good winning percentage for a major league baseball team.<<

With one less win, the Twins’ staff would be at .671. So they’re basically the norm.

by Johnny Safron on Aug 31, 2008 11:37 PM EDT reply actions

I suspected that

the Twins were about the norm, win % wise, when they get a QS. There are two keys here:

1. We’re getting a higher percentage of QS than most other teams in the league. The league average is 67 QS, so we’ve given ourselves an extra 7 (since we now have 74) QS compared to the average team.

2. Our win % in “non-QS” is a good bit higher than average. By my calculations, teams have gotten QS 49% of the time. If win % across all MLB is 67.3 in a QS, then across all MLB, win % would be 33.3% (A little bit greater than 1.0 – .673 due to more non-QS than QS). Our win % is 8% greater than average in non-QS.

So, looking at QS, relative to average, we get QS 5% more often and win non-QS 8% more often than the average MLB team.

by Adam Peterson on Sep 1, 2008 12:54 PM EDT up reply actions

Quality Start

Quality starts are a pretty damn arbitrary statistic, but looking at QS % does have some use, and is certainly more telling than win loss record. Perhaps we should start giving pitcher’s quality start, non quality start record. It would take the same form as win loss record so as to not confuse curmudgeonly sportswriters too much, and it would be a nice compromise. Like Scott Baker’s record would would be 13-9 (what it is anyway, interestingly) or Blackburn’s would be 16-11 instead of the unfairly suppressed 13-14 it is now. Meanwhile, Livan Hernandez would be a unimpressive 11-12 (Livan was funny, he didnt’ have many games where he jut missed the cutoff. he either would give the team a decent shot to win or totally explode).

Basic pitching lines could be like, say, Johan Santana: 22-6, 2.70 ERA. If we got really lucky, we’d see K/9 become a basic stat there too, but that may be asking for too much…

"You can't sit on a lead and run a few plays into the line and just kill the clock. You've got to throw the ball over the damn plate and give the other man his chance. That's why baseball is the greatest game of them all."
~ Earl Weaver
"In God we trust. All others must provide evidence."
~ Billy Beane

by AdamOnFirst on Sep 1, 2008 1:04 AM EDT reply actions

I like the idea

Yes, the QS is a fairly arbitrary statistic, but it’s a better measure than W-L. Livan’s stats were funny, feast or famine there.

by Adam Peterson on Sep 1, 2008 12:58 PM EDT up reply actions

But it

by Johnny Safron on Sep 1, 2008 1:29 PM EDT up reply actions

Bit it isn't arbitrary in the least

Try again.

Perhaps you are the one who use the word “arbitrary” in response to a previous statistical post,. Anyway, someone likes the workd. That statistical entry was not arbitrary, and neither is this one.

We know that 2 out of 3 times a team that gets a quality start wins. So it’s not arbitrary. It’s useful information. It’s synonomous with “giving your team a chance to win.”

Where it becomes a problem is with the pitchers who think that’s all they have to do. It also becomes a problem if it’s accepted as a fine accomplishment by fans. I don’t favor setting the bar so low as to think 6 innings and 3 runs allowed is fine work. If that becomes the litmus test for great pitching, that’s a bad thing.

But it appears based on research 20 seasons apart – and I’m not about to go through game logs for decades of games for all big-league teams to dig deeper – a quality start translates into a win 67 percent of the time. That’s worth knowing.

Of course, replacing W-L record with it is silly. Getting a win with a quality start still depends on your teammates’ defense and run support, no different than any other outing. And there are plenty of other stats to review to determine just how valid that W-L record is.

by Johnny Safron on Sep 1, 2008 1:42 PM EDT reply actions

Which is a better measure of performance?

Quality Start, or Win-Loss record? They’re both arbitrary, but I contend that the QS is a better measure of a pitcher’s performance than W-L.

by Adam Peterson on Sep 1, 2008 4:43 PM EDT up reply actions

Are you familiar with xFIP?

It is a truer measure of a pitcher’s raw ability without throwing in defense and other factors beyond the pitcher’s control.

Twins Fix
http://www.twinsfix.com

by Andersklasen on Sep 1, 2008 11:20 PM EDT up reply actions

Yes I am

I’d like to see xFIP right along side ERA for each pitcher, would give us an idea of how well the guy is actually pitching as well as how that has translated into runs.

I wasn’t claiming that QS is the only measure of performance, just thinking of something that could be presented in a fashion much similar to W-L.

by Adam Peterson on Sep 2, 2008 7:55 AM EDT up reply actions

Neither is arbitrary

You probably should consult the dictionary.

You, one person, choosing quality start over W-L record, now that is among the definitions for “arbitrary.”

by Johnny Safron on Sep 1, 2008 11:21 PM EDT reply actions

Arbitrary

I’m a fan of it because it is the closest thing to defining what the starters’ job is, minimally. But it is arbitrary in the sense that someone decided it was six innings and not seven or that it was three earned runs or less and not two or etc.

"You're thinking too much. Just have fun." -- Bennie "The Jet" Rodriguez in Sandlot

by cmathewson on Sep 2, 2008 12:07 AM EDT up reply actions

I still disagree with that

In theory if a team doesn’t have 2 or 3 relievers to hold a 5-3 lead going into the 7th, it’s not really the pitcher’s fault for a loss. I think 6 IP is the appropriate amount of work considering the fact that the majority of managers pay attention to pitch counts and tend to pull pitchers around 100 pitches as a risk management exercise. 7 just isn’t quite as attainable these days.

Not arbitrary.

by TMW on Sep 2, 2008 10:23 AM EDT up reply actions

One way the QS definition is useful

Is that it works out pretty close to 50-50. Just about half of all starts are QS, half are not. Increase to 7 innings or down to 2 ER, the bar is increased. This way you end up with a barometer that tells you as much as

by Adam Peterson on Sep 2, 2008 12:55 PM EDT up reply actions

Arbitrary

According to wiktionary:

Arbitrary is a term given to choices and actions which are considered to be done not by means of any underlying principle or logic, but by whim or some decidedly illogical formula

An example of an underlying principle is exhibited in OBP: It’s the percentage of times on base to plate appearances. The logic is in the percentages. Now, we might arbitrarily say that a quality OBP is .350 or better. But that definition is not derived from some logical principle.

An example of a metric derived from a logical principle related to pitching is the percentage of innings per start. Another example is ERA. Now, you could combine those two in a formula to come up with the stat that factors in innings pitched with runs allowed, and that would have a logical basis. But to define what the threshold is for quality innings/earned runs allowed per game is arbitrary.

I happen to agree with the arbitrary definition. But it is arbitrary.

"You're thinking too much. Just have fun." -- Bennie "The Jet" Rodriguez in Sandlot

by cmathewson on Sep 2, 2008 1:15 PM EDT up reply actions

I second that QS are abitrary

I mean, giving up 4 runs in 9 innings is better than giving up 3 in 6 IP, but 4 runs in 9 ip ain’t gonna get you a quality start. That said, I like QS as a metric, but it’s just a line in the sand that somebody at some point drew.

"I don't care about feelings." - Lou Piniella

by natetheskate on Sep 2, 2008 2:36 PM EDT up reply actions

The "someone" was sports writer John Lowe

Are you saying that he arbitrarily selected those numbers? For instance, Lowe was looking for a method to determine a pitcher’s contribution independent of W-L record. That’s not arbitrary. Are you suggesting that Lowe randomly chose 6 innings and 3 ER? What’s the story behind Lowe creating the quality start?

by Johnny Safron on Sep 4, 2008 12:14 AM EDT up reply actions

Arbitrary is not random

And Lowe did not randomly choose the 6/3 ratio. As I mentioned, I think the ratio of QS to non-QS is as good as, say a 3.5 xFIP in separating the wheat from the chaff. But neither definition is determined entirely by mathematical principles. They depend upon someone drawing a distinction for the sake of convenience. As I said, he might have insisted on seven innings or two runs or whatever and he would use the same logic as he did with 6 and 3.

"You're thinking too much. Just have fun." -- Bennie "The Jet" Rodriguez in Sandlot

by cmathewson on Sep 4, 2008 1:09 AM EDT up reply actions

Are we really having a grammar discussion?

Do we think it’s a good or a bad statistic? If bad, is there a better, similar way to quantify a pitcher’s start as “good” or “bad”?

by Adam Peterson on Sep 4, 2008 8:26 AM EDT up reply actions

Well, can't help it

It’s an occupational hazard. Plus I studied for a doctorate in the philosophy of language for six years. That’s all about the meaning of terms like arbitrary.

But I agree, it’s silly to argue about the definition of terms when you basically agree on the central point: Quality Starts are a useful way of evaluating a pitcher.

"You're thinking too much. Just have fun." -- Bennie "The Jet" Rodriguez in Sandlot

by cmathewson on Sep 4, 2008 9:32 AM EDT up reply actions

I understand

I’m an engineer, can’t stay away from the numbers. ..

by Adam Peterson on Sep 4, 2008 9:38 AM EDT up reply actions

another problem with QS stat

how many starts that qualify as quality starts achieve exactly 6 ip and 3 runs? i hazard to guess that team records in those pitching performances are significantly worse than for all QS’s which include shutouts etc. and inflate the value of the stat.

by slower than slowey on Sep 2, 2008 5:09 PM EDT reply actions

Of course they're worse

I’m not sure how significant the difference is, though. I suspect that a 6 IP / 3 ER start probably gives a team over a 50% chance of winning, but probably not by much. Does that inflate the value of the stat? IMO, no. The key here is that a QS means a starter puts his team in position to win the game, and you have a barometer of performance that maximizes ability to classify “good” versus “poor”.

What do I mean? We could set the bar very high (complete game shutouts) or very low (at least one IP). However, either of those stats wouldn’t differentiate very well across the league…

by Adam Peterson on Sep 3, 2008 7:47 AM EDT up reply actions