SoxProspects News
|
|
|
|
Legal
Forum Ground Rules
The views expressed by the members of this Forum do not necessarily reflect the views of SoxProspects, LLC.
© 2003-2024 SoxProspects, LLC
|
|
|
|
|
Forum Home | Search | My Profile | Messages | Members | Help |
Welcome Guest. Please Login or Register.
Middlebrooks' 2013 Struggles
|
Post by jmei on Sept 7, 2013 11:11:30 GMT -5
Is that with a chi-squared test? In a sample this small (216/90 PAs), I'm not sure that methodology is appropriate or useful. Remember, getting five heads in a row gets you under p=.05 as well.
|
|
ericmvan
Veteran
Supposed to be working on something more important
Posts: 9,016
|
Post by ericmvan on Sept 7, 2013 11:29:39 GMT -5
Is that with a chi-squared test? In a sample this small (216/90 PAs), I'm not sure that methodology is appropriate or useful. Remember, getting five heads in a row gets you under p=.05 as well. It is chi-square, and it only works accurately with all cell values >=5. Or at least that's what they taught me in 1971. To get a chi-square p < .05 tossing a coin, you'd have to toss it 32 times, and get 5 heads in the first 16, and then 11. What WMB did is like tossing a coin 40 times, and getting 5 heads in the first 20 and 15 heads in the second twenty. You are all welcome to try that instead of watching today's game. The key ideas behind significance testing are that a) the result by definition tells you whether the sample size was large enough, and b) however, the resulting p value must be interpreted, in terms of both a priori hypothesized causes, and the number of tests being performed.There's an immense difference between having a hypothesis and testing only the variables that are thought to be affected, versus trolling through reams of data and noticing and testing all the large anomalies. In the latter case, if you do construct a hypothesis to explain an anomaly, ideally that hypothesis makes another completely unrelated prediction that you can then test. Whenever possible you want to end up with the hypothesis first, then the examination of evidence.
|
|
|
Post by wcsoxfan on Sept 7, 2013 11:45:24 GMT -5
Well, here's the funny thing. His improvement in K rate since the call-up, from .279 to .216, isn't close to being statistically significant. The p value is .256, meaning that one guy in four would show such an improvement just at random. His improvement in BB rate, from .042 to .068, is even less significant ( p = .338). You can multiply those together, to measure the chance of them happening simultaneously, and it still doesn't pass the scientific standard of p < .05. In fact, you can throw in his improvement in HR/Contact (.062 to .081, p = .626), inflated by measuring it at the peak of a hot streak, and it still falls short of getting The New Will Middlebrooks approved by the FDA. So much for the "three true outcomes." But you know what is massively significant? His BABIP:.221 before Pawtucket, .404 afterwards. The p value of that is .009, or less than 1 chance in a thousand of being random. So I faked you out. Rather than "don't trust this small sample to demonstrate that he's been better," the actual point is (not for the first time) "don't assume hitter's BABIP is luck." In this case, a real and decent-sized but not statistically significant improvement in strike zone command has led to a hugely significant improvement in hitting the ball hard. Thank you for including these numbers - I always enjoy using p and t tests while analyzing data [even though they aren't the end-all be-all, they are quick, fun (is that weird?) and very useful] But I think your conclusion is faulty. You discovered that the level in which he is getting the ball in play is significant in judging his future success. That is likely due to hitting the ball harder (as baseball fans we can all accept this I think) and that may be due to an 'improvement in strike zone command'. But you also showed that we don't know yet whether he truly has an improved strike zone command. Although I hope you are correct and 'feel' you probably are, we really can't say for certain whether he has improved his plate discipline to a level which can be predictive of future results.
|
|
|
Post by jmei on Sept 7, 2013 12:10:48 GMT -5
Is that with a chi-squared test? In a sample this small (216/90 PAs), I'm not sure that methodology is appropriate or useful. Remember, getting five heads in a row gets you under p=.05 as well. It is chi-square, and it only works accurately with all cell values >=5. Or at least that's what they taught me in 1971. To get a chi-square p < .05 tossing a coin, you'd have to toss it 32 times, and get 5 heads in the first 16, and then 11. What WMB did is like tossing a coin 40 times, and getting 5 heads in the first 20 and 15 heads in the second twenty. You are all welcome to try that instead of watching today's game. The key ideas behind significance testing are that a) the result by definition tells you whether the sample size was large enough, and b) however, the resulting p value must be interpreted, in terms of both a priori hypothesized causes, and the number of tests being performed.There's an immense difference between having a hypothesis and testing only the variables that are thought to be affected, versus trolling through reams of data and noticing and testing all the large anomalies. In the latter case, if you do construct a hypothesis to explain an anomaly, ideally that hypothesis makes another completely unrelated prediction that you can then test. Whenever possible you want to end up with the hypothesis first, then the examination of evidence. The coin flipping example was a z-test, which I should have clarified. Thanks for the refresher on chi-squared tests. Is there any particular reason to think that BABIP or K/BB/HR rates follow a chi-squared distribution? I imagine that even if they don't, it's close enough that for our quick and dirty purposes we can just squint and forget the difference. The other problem with hypo testing is that I'm not sure it's predictive enough when compared to other projection methods to be worth the effort, but as an explanatory tool, it's definitely useful. The other interesting thing is that Middlebrooks' batted ball profile is not all that different before and after his callup. He's hitting about the same number of line drives and infield pop-ups (and even getting fewer infield hits).
|
|
|
Post by jchang on Sept 7, 2013 14:05:01 GMT -5
I don't see any reason to be surprised at the adjustment difficulty WMB had earlier this year, or any that could still happen in the next year or two. Perhaps our frame of reference has been affected by Youk, Pedroia and Ells, that any less is a bust. Lowrie had adjustment/injury issues. Nava is probably a different case because he did not project to be an above average player back when he was a non/post-prospect. Also, I do not see how WMB's SO are any different from other heavy HR hitters. Chris Davis was hot his first year, then slumped the next 2 before the O's "filched" him for some guy named Uehara, ... oh wait, never mind. Below: MLB career
Player Avg SO BB HR% XBH% WMB 0.262 27.1% 5.5% 5.27% 10.9% C Davis 0.268 33.5% 8.3% 6.18% 12.1% Hamilton 0.294 22.8% 9.2% 5.42% 12.1% J Bautista 0.254 22.3% 16.0% 5.83% 11.4% Teixeira 0.278 20.0% 13.2% 5.96% 12.5% Cabrera 0.321 19.4% 12.8% 5.92% 12.8% Pujols 0.321 11.4% 14.6% 6.73% 14.1%
left off Miguel Cabrera because he is in the elite category, and I think WMB should be in the above average to all star range. So it would be nice if WMB could approach Bautista SO/BB rates, but HR power with decent average is not something to be dismissed. Note: Both Davis, Bautista and Cabrera had comparable HR and XBH rates at age 23-24, with a surge is their late 20's. I don't think it will be easy to find a prospect that will deliver Pujols numbers.
|
|
|
Post by onbase on Sept 7, 2013 17:35:34 GMT -5
His BABIP:.221 before Pawtucket, .404 afterwards. The p value of that is .009, or less than 1 chance in a thousand of being random. So I faked you out. Rather than "don't trust this small sample to demonstrate that he's been better," the actual point is (not for the first time) "don't assume hitter's BABIP is luck." In this case, a real and decent-sized but not statistically significant improvement in strike zone command has led to a hugely significant improvement in hitting the ball hard. It seems intuitive to me that BABIP must have both a luck component and a skill component, but I have no idea how you'd compute the percentages. - How do you know when a high or low BABIP is meaningful or sustainable if you don't have multiple years to look at and a career "norm" to compare to? - Why are Pujols at .258/.306 and Trout at .391/373 for 2013/career? How much of the career difference is speed?
|
|
|
Post by grandsalami on Sept 7, 2013 17:45:57 GMT -5
|
|
|
Post by pedroelgrande on Sept 7, 2013 18:09:00 GMT -5
Or the Brewers are crazy. I remember they offered JJ Hardy for Buchholz and Theo replied "LOL"
Don't know if that was serious.
|
|
ericmvan
Veteran
Supposed to be working on something more important
Posts: 9,016
|
Post by ericmvan on Sept 7, 2013 21:43:49 GMT -5
Thank you for including these numbers - I always enjoy using p and t tests while analyzing data [even though they aren't the end-all be-all, they are quick, fun (is that weird?) and very useful] But I think your conclusion is faulty. You discovered that the level in which he is getting the ball in play is significant in judging his future success. That is likely due to hitting the ball harder (as baseball fans we can all accept this I think) and that may be due to an 'improvement in strike zone command'. But you also showed that we don't know yet whether he truly has an improved strike zone command. Although I hope you are correct and 'feel' you probably are, we really can't say for certain whether he has improved his plate discipline to a level which can be predictive of future results. Here's the way I think, and why I think it is a sound conclusion. We start with the observation that his strike zone command improvement has a 1-in-11.6 chance of happening randomly. We haven't looked at 12 different guy's before-and-after splits, just his, because he looks better up there, so we don't have to adjust that finding because we were data-fishing. The data tells us that there's a 91% chance that he has improved his command. That is not enough to be sure. But we still suspect it's probably true. We then say, if it were true, he should be hitting the ball harder. That's a further prediction of the hypothesis. Is he? He is. His HR rate is up--insignificantly so, but up is still better than down. His BABIP is up so much that it's almost impossible to be random. Now, there's almost certainly a lot of luck involved in there -- bad luck before, and good luck after -- but the point is that the change is too large to be explained by luck alone; there must be a skill component as well. That the hypothesis predicted something, and we can be fairly certain of that something, greatly increases our confidence in it. It would be very strange indeed for the strike zone command to be random and the evident skill component of his BABIP increase to be the result of something else, something we have no clue about or indication of, when we know the two are ordinarily closely related, causally. We are therefore grateful for the BABIP luck, because we desired to sleep restfully tonight, and now we can do so, this question being settled (and the decision to attack Syria being not our responsibility).
|
|
|
Post by ramireja on Sept 7, 2013 22:03:30 GMT -5
Isn't a major assumption of chi-square tests that the observations being tested are independent from one another? I may be mistaken, but I'm not sure the use of chi-square tests are appropriate for data in which all the observations come from the same player, in this case...Middlebrooks.
|
|
|
Post by larrycook on Sept 8, 2013 9:56:10 GMT -5
Or maybe when Middlebrooks is going well, he is a semi-patient hitter with good power but a lot of strike outs.
When he slumps, he gets very impatient and widens the strike zone and reverts to being a minor league hitter.
If took almost a season, but Middlebrooks has made the adjustment. Next pitchers will make another adjustment in how they pitch to him.
And how Middlebrooks responds to that will determine if he has success in 2014 or not.
|
|
|
Post by Guidas on Sept 8, 2013 10:26:09 GMT -5
Aside from the stats, I saw an interview this weekend Gammo did with Middlebrooks where Will said he changed his stance, that he had been an open stance guy with a small stride since high school and now he has gone to closed stance with a toe pivot (instead of tap with slight stride). This is a significant adjustment and it seems to have paid tremendous dividends.
For those who never played the game beyond high school this is not an easy change to implement when facing pitching at a high level. What he said it's doing for him is: 1) not pulling his body to left field and letting him stay up the middle better when he hits the ball, and 2) letting the ball travel just a bit deeper than it was before because, by not striding toward the pitcher, he is meeting the ball about a foot to 18 inches deeper than where he was making contact before .
I noticed the difference in his approach right away, and as his confidence improved over his first few games back he has gone from singles to generating more power. What is most impressive is he seems to be recognizing pitches better and swinging outside the zone much less.
I can't understate how significant this adjustment is (changing stance and stride - both become deeply conditioned and habitual), and how difficult it is to go from an open to closed stance in such a short period of time and gain comfort in it, especially If he's been open-stanced for more than 8 years. It literally forces him to look at the ball differently . In fact, most players go to an open stance because they claim it helps them with pitch recognition; with Middlebrooks, it appears to be the opposite. We are in small sample territory, but if he can continue these adjustments and maintains this patient approach (i.e. not chasing so often out of the zone as he was at the beginning of the year), his OBP may well climb into a range that would make him an above average player at his position (.340+).
|
|
|
Post by Don Caballero on Sept 8, 2013 12:22:33 GMT -5
Or the Brewers are crazy. I remember they offered JJ Hardy for Buchholz and Theo replied "LOL" Don't know if that was serious. I hope it was, because it sounds too funny to not be.
|
|
|
Post by gregblossersbelly on Sept 8, 2013 17:19:35 GMT -5
Kid is growing before our very eyes. Slugging 3b who can field his position. No pressure to even be the middle of the order bat. Seems to be ideal for something like a 7th place hitter going forward.
|
|
|