Two Myths I'm Ready to Debunk

[hoosiers]

http://sports.espn.go.com/espn/page2/story?page=keri/070214

With all these tools at their disposal, you might expect the experts to achieve huge success rates, routinely nailing the vast majority of their projections. But various studies, done by industry leaders and outsiders alike, peg the success rate for a typical weighted three-year projection system like Marcel at about 65 percent. The goal for primo projectionists is to eke out a bit more accuracy, for a year-to-year success rate approaching 70 percent. A perfect projection system, or even something close to it, is widely considered to be impossible -- at least until stat-generating robots replace human beings at Yankee Stadium.

Looks like "about 65%". I agree with making the best decisions based on available data, but I must say that number is far below the perceived likelihoods implied by the statistical-based posters here. And, based on Witchy's post, I know I'm not alone.

[rolliefingers]

http://sports.espn.go.com/espn/page2/story?page=keri/070214

Looks like "about 65%". I agree with making the best decisions based on available data, but I must say that number is far below the perceived likelihoods implied by the statistical-based posters here. And, based on Witchy's post, I know I'm not alone.

I would rather put my faith in numbers than in someone's "gut instinct". A 65 percent success rate, when you're dealing with PREDICTIONS, is pretty damned good, if you ask me.

[rolliefingers]

They will say, and have, that they have never said it is/was a 100% given that MiLB stats are a reliable predictor of MLB performance, however, they do 100% of the time go with the guy that has the best MiLB stats... is it also possible that a guy with average to poor MiLB stats can out-perform another MiLB player with considerably better stats at the MLB level? Because this is where they ALWAYS go with stats when chosing who to give playing time to...

It's very possible over a small sample size, and it gets increasingly less likely as the sample increases.

[tywright]

The being said, if everything else is equal and one guy is putting up better numbers than the other, of course you look towards the guy who has performed better...Isn't that just common sense?

Not so fast...sometimes that doesn't work. For instance:

In 2002, both players were 23 and both were in AAA, but in different leagues so the stats could be affected by park differences.

Which player would you take based on these stats?

Player A .265 (95/359) .403 OBP .524 SLG .927 OPS

24 2B 23 HR 55 RBI 83BB/121K

Player B .263 (122/464) .329 OBP .461 SLG .790 OPS

39 2B 17 HR 70 RBI 46BB/89K

The BA is about the same, but OBP is a large disparity. Player A displays more power and better patience at the plate. Most scouts would take Player A. However, Player A is Jack Cust and Player B is Chase Utley. Utley didn't break out until the following year. He was quite the aberration since he was averaging .260 in his 1st 2 years as a pro, but all of sudden was hitting .320+ in his 2nd year (3rd overall as pro) in AAA. Whereas Cust signed with the O's and began to lose his luster.

[DrungoHazewood]

http://sports.espn.go.com/espn/page2/story?page=keri/070214

Looks like "about 65%". I agree with making the best decisions based on available data, but I must say that number is far below the perceived likelihoods implied by the statistical-based posters here. And, based on Witchy's post, I know I'm not alone.

That's damned good. I think your perception of what I think is what's way off.

[frankpembleton]

Not so fast...sometimes that doesn't work. For instance:

In 2002, both players were 23 and both were in AAA, but in different leagues (doesn't really matter with these stats).

Which player would you take based on these stats?

Player A .265 (95/359) .403 OBP .524 SLG .927 OPS

24 2B 23 HR 55 RBI 83BB/121K

Player B .263 (122/464) .329 OBP .461 SLG .790 OPS

39 2B 17 HR 70 RBI 46BB/89K

Player A is Jack Cust

Player B is Chase Utley

What were there stats leading up to that year. Also, Chase Utley plays second base and his numbers at the position are more valuable than Cust's at his positions.

Oh, and Cust was never given the appropriate chance to succeed, so how do we know how he would have done given the same number of at bats as Utley.

Cust is turning into quite a player given the chance if you haven't noticed....

[DrungoHazewood]

I ran some numbers comparing the 2007 PECOTAs to the 22 major league rookies who's accumulated 250 or more PAs this year. PECOTAs for these players were based on Davenport translations of their minor league numbers.

I took the absolute difference between the players' AVG, OBA, and SLG.

Then I figured the average, the standard deviation, and min deviation, and maximum deviation.

This is a very small sample. This is nothing like a comprehensive study. I'm sure you guys will shoot all kinds of holes in it. But here it is (hope the formatting isn't too awful):

		PECOTA				Real				Absolute difference		Last	First	BA	OBP	SLG		AVG	OBP	SLG		AVG	OBP	SLGBraun	Ryan	0.283	0.341	0.504		0.328	0.373	0.641		0.045	0.032	0.137Buck	Travis	0.288	0.346	0.455		0.288	0.377	0.474		0.000	0.031	0.019Butler	Billy	0.295	0.347	0.455		0.295	0.353	0.450		0.000	0.006	0.005Escobar	Yunel	0.283	0.349	0.389		0.318	0.375	0.436		0.035	0.026	0.047Fields	Josh	0.260	0.328	0.459		0.229	0.284	0.437		0.031	0.044	0.022Gordon	Alex	0.282	0.364	0.511		0.258	0.324	0.427		0.024	0.040	0.084Hamilton Josh	0.253	0.303	0.403		0.292	0.368	0.554		0.039	0.065	0.151Harris	Brendan	0.259	0.314	0.390		0.284	0.341	0.425		0.025	0.027	0.035Hopper	Norris	0.270	0.312	0.313		0.324	0.362	0.385		0.054	0.050	0.072Iwamura	Akinori	0.275	0.353	0.449		0.285	0.358	0.412		0.010	0.005	0.037Kouzmanoff K.	0.290	0.348	0.499		0.262	0.316	0.444		0.028	0.032	0.055Lind	Adam	0.289	0.349	0.493		0.230	0.273	0.381		0.059	0.076	0.112Loney	James	0.295	0.351	0.470		0.322	0.372	0.522		0.027	0.021	0.052Owens	Jerry	0.271	0.324	0.351		0.246	0.307	0.293		0.025	0.017	0.058Pedroia	Dustin	0.294	0.360	0.431		0.327	0.391	0.452		0.033	0.031	0.021Pena	Tony	0.244	0.279	0.337		0.256	0.276	0.335		0.012	0.003	0.002Pence	Hunter	0.278	0.338	0.489		0.326	0.361	0.548		0.048	0.023	0.059Reynolds Mark	0.260	0.325	0.483		0.268	0.330	0.473		0.008	0.005	0.010Ruiz	Carlos	0.278	0.336	0.439		0.260	0.334	0.409		0.018	0.002	0.030Tulowitzki T.  	0.291	0.349	0.461		0.294	0.363	0.476		0.003	0.014	0.015Willits	Reggie	0.250	0.325	0.339		0.291	0.393	0.342		0.041	0.068	0.003Young	C.	0.283	0.363	0.541		0.237	0.294	0.472		0.046	0.069	0.069								Average	0.028	0.031	0.050								St Dev	0.017	0.023	0.042								Max	0.059	0.076	0.151								Min	0.000	0.002	0.002

So in this extremely small sample, PECOTA's standard deviation was ±17 points of batting average, ±23 points of OBP, and ±42 points of SLG. That means that if you projected Jon Knott to a .250/.325/.450 line he'd have something like a 70% chance of being somewhere between .233/.302/.408 and .267/.348/.492. If I have all my assumptions correct...

[rolliefingers]

Not so fast...sometimes that doesn't work. For instance:

In 2002, both players were 23 and both were in AAA, but in different leagues (doesn't really matter with these stats).

Which player would you take based on these stats?

Player A .265 (95/359) .403 OBP .524 SLG .927 OPS

24 2B 23 HR 55 RBI 83BB/121K

Player B .263 (122/464) .329 OBP .461 SLG .790 OPS

39 2B 17 HR 70 RBI 46BB/89K

Player A is Jack Cust

Player B is Chase Utley

YES, IT DOES MATTER! Without checking, I'm gonna say that Cust was in the PCL, and Utley was in the IL. That makes A TON of difference. So does the fact that Utley is a good defender. Obviously, you take those things into account, and nobody's saying not to.

Nice strawman, though.

[Sports Guy]

Not so fast...sometimes that doesn't work. For instance:

In 2002, both players were 23 and both were in AAA, but in different leagues (doesn't really matter with these stats).

Which player would you take based on these stats?

Player A .265 (95/359) .403 OBP .524 SLG .927 OPS

24 2B 23 HR 55 RBI 83BB/121K

Player B .263 (122/464) .329 OBP .461 SLG .790 OPS

39 2B 17 HR 70 RBI 46BB/89K

Player A is Jack Cust

Player B is Chase Utley

First of all, no one has said it always works.

Secondly, you would have said at that time that Utley was the better all around player because Cust was a defensive liability.

For you to throw out league and park effects is a joke...The PCL is a much better hitters league...The Intl league is a pitchers league full of pitcher's parks.

BTW, Utley had a 350+ OBP in 2002:

http://www.thebaseballcube.com/players/U/Chase-Utley.shtml

So Utley had an 813 OPS in a much better pitchers league in a much harder hitters park....I don't think your example is all that great.

BTW, Utley's career OPS is 40 points higher than Cust playing in a much better hitters park than Cust has.

[weams]

Carlos Pena signed for $800K. The Orioles put some bait on the hook there, but decided not to reel him into the boat. Tampa Bay's entire roster cost them $24.1 million. Of that figure, $13.9M is tied up into Crawford, Fossum, Iwamura, Young and Seo. The other $10 million or so goes to twenty guys. Some of those players would be adequate replacements for Bako, Gibbons, Payton and others. The extra $69 million we spent on payroll has gotten us one extra game in the standings ahead of Tampa Bay.

The Florida Marlins spent $30 million, of which nearly 2/3 is tied up in Willis, Cabrera, Olivo, and our old pal, Julio. Once again, this leaves about $10 million invested in over twenty players.

The Washington Nationals payroll of $37.4 million, $26 million of which goes to Johnson, Guzman, Cordero, Lopez, Schneider, Kearns, and Ayala. The story once again is the same with $10-$11 million tied up in twenty other players. Dmitri Young was signed for $500,000.

Somehow these three teams, and others, manage to primarily fill their rosters with guys making under a million dollars a year. Myth?

Rollie you have too many PM's Agagn!

[tywright]

What were there stats leading up to that year. Also, Chase Utley plays second base and his numbers at the position are more valuable than Cust's at his positions.

Oh, and Cust was never given the appropriate chance to succeed, so how do we know how he would have done given the same number of at bats as Utley.

Cust is turning into quite a player given the chance if you haven't noticed....

Utley was not doing much prior to that season and finally broke out when he turned 24 (3rd pro year). Cust on the other hand had 3 prior seasons of .930+ OPS.

Cust had no defensive position that's why he wasn't going to succeed. And he's still only hitting .255 with 142Ks, so I wouldn't say he's turning into a great player.

[tywright]

YES, IT DOES MATTER! Without checking, I'm gonna say that Cust was in the PCL, and Utley was in the IL. That makes A TON of difference. So does the fact that Utley is a good defender. Obviously, you take those things into account, and nobody's saying not to.

Nice strawman, though.

You really think Cust was a great player because he was in the PCL? He had much better seasons prior to 2001 and 2002 when he was in the PCL.

I was not taking into account defensive ability, just straight hitting stats.

[tywright]

First of all, no one has said it always works.

Secondly, you would have said at that time that Utley was the better all around player because Cust was a defensive liability.

For you to throw out league and park effects is a joke...The PCL is a much better hitters league...The Intl league is a pitchers league full of pitcher's parks.

BTW, Utley had a 350+ OBP in 2002:

http://www.thebaseballcube.com/players/U/Chase-Utley.shtml

So Utley had an 813 OPS in a much better pitchers league in a much harder hitters park....I don't think your example is all that great.

BTW, Utley's career OPS is 40 points higher than Cust playing in a much better hitters park than Cust has.

Utley wasn't necessarily a better prospect. He was never ranked in the top 100 like Cust was until Utley posted his breakout season. And Utley had 28 errors in 2002 and a Field PCt of .918. So his defense was not up to par.

I was using Baseball reference's minor league stats. Utley did have 20 HBP in 2002 so his OBP might be off on Baseball Reference.

[Sports Guy]

Utley was not doing much prior to that season and finally broke out when he turned 24 (3rd pro year). Cust on the other hand had 3 prior seasons of .930+ OPS.

Cust had no defensive position that's why he wasn't going to succeed. And he's still only hitting .255 with 142Ks, so I wouldn't say he's turning into a great player.

Utley was 23 in 2004...He put up an 813 OPS, which was 67 points higher than he did in A+ ball...That is a good sign.

Utley also improved his BB and K rates as he moved from A+ to AA.

[tywright]

BTW, Utley's career OPS is 40 points higher than Cust

Who would have thought that after seeing their minor league stats? Hmmm