J'Accuse

[JDubs]

I'm not sure how relevant last year is, frankly. Why is last year "the mean"?

Yeah, "regression to the mean" is overused to explain tenuous opinions, IMO.

[weams]

I find it odd that 10 of your 12 posts involve the Blue Jays.

J'Accuse?

[T. Legend]

I'm not sure how relevant last year is, frankly. Why is last year "the mean"?

Before this year, he had given up 86 home runs in 732 innings, or one every 12.....to say he's improved to cut down his home run totals that much from his career (or from last year) is tough to swallow IMHO.

Then again, he's a definite upgrade over Guthrie so far, so I can't be too negative.

[weams]

Before this year, he had given up 86 home runs in 732 innings, or one every 12.....to say he's improved to cut down his home run totals that much from his career (or from last year) is tough to swallow IMHO.

Then again, he's a definite upgrade over Guthrie so far, so I can't be too negative.

There is no question that Jason Hammel is someone who has improved as he has aged to his late twenties.

[btownoriole]

Except for the "small" fact that Hammel has given up three dingers ALL year and yet gave up FOUR in one game yesterday.

All with the bases empty...

The fact that 5 of Hammel's 7 HRs allowed this year have been in Toronto raises my suspicions. (along with the other accusations). It is interesting to compare the pitching lines of the O's who have faced the Jays at both Camden Yards and Rogers Center (Arrieta has not faced the Jays at home yet this year):

Hammel (Rogers Center): 11.2 IP, 15 H, 6 ER, 3 BB, 8 K, 5 HR

Hammel (OPACY): 7 IP, 4 H, 0 ER, 1 BB, 7 K, 0 HR

Hunter (Rogers Center): 9 IP, 15 H, 9 ER, 2 BB, 2 K, 6 HR

Hunter (OPACY): 6 IP, 3 H, 1 ER, 3 BB, 3 K, 1 HR

Matusz (Rogers Center): 5.2 IP, 7 H, 5 ER, 4 BB, 4 K, 2 HR

Matusz (OPACY): 6 IP, 4 H, 0 ER, 2 BB, 3 K, 0 HR

Totals (Rogers Center - 5 starts): 26.1 IP, 37 H, 20 ER, 9 BB, 14 K, 13 HR

Totals (OPACY - 3 starts): 19 IP, 11 H, 1 ER, 6 BB, 13K, 1 HR

[Can_of_corn]

And I find it odd that someone feels the need to go digging through an obvious lurker's message history....we all get frustrated by the O's from time to time, there doesn't have to be some nefarious explanation for it.

My interest was piqued as to why someone that has such a low post rate would suddenly decide to make a one person stand on this particular issue. So yes I "dug", by left clicking your name, and scanned your dozen posts.

You wouldn't find your sudden zeal to defend the Jays odd from the outside?

[weams]

All with the bases empty...

The fact that 5 of Hammel's 7 HRs allowed this year have been in Toronto raises my suspicions. (along with the other accusations). It is interesting to compare the pitching lines of the O's who have faced the Jays at both Camden Yards and Rogers Center (Arrieta has not faced the Jays at home yet this year):

Hammel (Rogers Center): 11.2 IP, 15 H, 6 ER, 3 BB, 8 K, 5 HR

Hammel (OPACY): 7 IP, 4 H, 0 ER, 1 BB, 7 K, 0 HR

Hunter (Rogers Center): 9 IP, 15 H, 9 ER, 2 BB, 2 K, 6 HR

Hunter (OPACY): 6 IP, 3 H, 1 ER, 3 BB, 3 K, 1 HR

Matusz (Rogers Center): 5.2 IP, 7 H, 5 ER, 4 BB, 4 K, 2 HR

Matusz (OPACY): 6 IP, 4 H, 0 ER, 2 BB, 3 K, 0 HR

Totals (Rogers Center - 5 starts): 26.1 IP, 37 H, 20 ER, 9 BB, 14 K, 13 HR

Totals (OPACY - 3 starts): 19 IP, 11 H, 1 ER, 6 BB, 13K, 1 HR

Nice research

[Lucky Jim]

Before this year, he had given up 86 home runs in 732 innings, or one every 12.....to say he's improved to cut down his home run totals that much from his career (or from last year) is tough to swallow IMHO.

Then again, he's a definite upgrade over Guthrie so far, so I can't be too negative.

But it's nearly impossible to control for confounding factors. If you look at his pitch values relative to last year, there's a huge gulf. Enormous. I said at the time we traded for him that I suspected the O's had identified him as someone who would see significant uptick in stuff outside of Coors, given the the fact that scouting reports (plus-) and pitch values (negative) on his secondaries were widely discrepant. Coors is known to suppress breaking pitch value. He's also improved his 2-seamer, leading to a high GB%. He simply appears better - but it's a improvement that is (for now) verified by the numbers.

A regression to the mean doesn't mean that a player will get worse because he's been bad in the past. Cliff Lee in 2008 is an example - he wasn't lucky, even though his numbers improved greatly. You would have been wrong to say that he was likely to "return to the mean" - though it wasn't impossible that he would simply start to suck again.

In sum, a regression to the mean should be used when we're talking about the tendency of uncontrollable factors to revert back to their baseline - for some pitchers, whose success is riding along that inflation, that means performance, too. But there are no "uncontrollable" factors w/r/t Hammel, save for his LOB%.

Pointing out a year where he was bad and a year where he was good and then predicting something doesn't really do much in the way of analysis, and it certainly doesn't have anything to do with a "mean."

[Lucky Jim]

All with the bases empty...

The fact that 5 of Hammel's 7 HRs allowed this year have been in Toronto raises my suspicions. (along with the other accusations). It is interesting to compare the pitching lines of the O's who have faced the Jays at both Camden Yards and Rogers Center (Arrieta has not faced the Jays at home yet this year):

Hammel (Rogers Center): 11.2 IP, 15 H, 6 ER, 3 BB, 8 K, 5 HR

Hammel (OPACY): 7 IP, 4 H, 0 ER, 1 BB, 7 K, 0 HR

Hunter (Rogers Center): 9 IP, 15 H, 9 ER, 2 BB, 2 K, 6 HR

Hunter (OPACY): 6 IP, 3 H, 1 ER, 3 BB, 3 K, 1 HR

Matusz (Rogers Center): 5.2 IP, 7 H, 5 ER, 4 BB, 4 K, 2 HR

Matusz (OPACY): 6 IP, 4 H, 0 ER, 2 BB, 3 K, 0 HR

Totals (Rogers Center - 5 starts): 26.1 IP, 37 H, 20 ER, 9 BB, 14 K, 13 HR

Totals (OPACY - 3 starts): 19 IP, 11 H, 1 ER, 6 BB, 13K, 1 HR

Hunter also gave up 4 solo HRs in that Toronto start.

10 of the 13 HRs have been solo, in fact.

[Todd-O]

There is prior speculation concerning the Jays and stealing signs. Tipping pitches and stealing signs, legally, is part of the game.

Having an outside party steal signs is cheating.

Of course tipping a pitch is legal. It's the pitchers responsibility to have the same pattern/deliver across all pitches!!

I believe with Randy Johnson (1997) he was holding his glove at a different angle when he was throwing his slider?

[T. Legend]

My interest was piqued as to why someone that has such a low post rate would suddenly decide to make a one person stand on this particular issue. So yes I "dug", by left clicking your name, and scanned your dozen posts.

You wouldn't find your sudden zeal to defend the Jays odd from the outside?

Fair enough, but honestly we've had 15 years of losing baseball (really, really bad losing baseball), so I have become particularly sensitive to excuses....and then I see stuff like this:

All with the bases empty...

The fact that 5 of Hammel's 7 HRs allowed this year have been in Toronto raises my suspicions. (along with the other accusations). It is interesting to compare the pitching lines of the O's who have faced the Jays at both Camden Yards and Rogers Center (Arrieta has not faced the Jays at home yet this year):

Hammel (Rogers Center): 11.2 IP, 15 H, 6 ER, 3 BB, 8 K, 5 HR

Hammel (OPACY): 7 IP, 4 H, 0 ER, 1 BB, 7 K, 0 HR

Hunter (Rogers Center): 9 IP, 15 H, 9 ER, 2 BB, 2 K, 6 HR

Hunter (OPACY): 6 IP, 3 H, 1 ER, 3 BB, 3 K, 1 HR

Matusz (Rogers Center): 5.2 IP, 7 H, 5 ER, 4 BB, 4 K, 2 HR

Matusz (OPACY): 6 IP, 4 H, 0 ER, 2 BB, 3 K, 0 HR

Totals (Rogers Center - 5 starts): 26.1 IP, 37 H, 20 ER, 9 BB, 14 K, 13 HR

Totals (OPACY - 3 starts): 19 IP, 11 H, 1 ER, 6 BB, 13K, 1 HR

This is what's called a "small sample size". Comparing 3 and 5 starts tells me virtually nothing.

Instead, let's look at last year, when the BJ's and Orioles played 18 times. That shows me a lot more:

In 9 games in Toronto, the Jays averaged 4.33 runs. The Orioles averages 4.22 runs.

In 9 games in Baltimore, the Jays averaged 6.44 runs. The Orioles averaged 4.11 runs.

Those are the facts. Make whatever inference you want from them....

[Lucky Jim]

Fair enough, but honestly we've had 15 years of losing baseball (really, really bad losing baseball), so I have become particularly sensitive to excuses....and then I see stuff like this:

This is what's called a "small sample size". Comparing 3 and 5 starts tells me virtually nothing.

Instead, let's look at last year, when the BJ's and Orioles played 18 times. That shows me a lot more:

In 9 games in Toronto, the Jays averaged 4.33 runs. The Orioles averages 4.22 runs.

In 9 games in Baltimore, the Jays averaged 6.44 runs. The Orioles averaged 4.11 runs.

Those are the facts. Make whatever inference you want from them....

You have strange ideas about statistics.

I mean, this was prominently posted in this thread, taking the sample of an entire year, across multiple teams:

Now, by themselves, the above splits aren't conclusive, so to measure the effect of Rogers Centre more precisely, The Mag consulted with Wyers. He has developed a method that generates park factors by comparing a player's performance in any given park with his performance in all other parks, not just in road games for that player. This reduces statistical noise and offers a better estimate of how a park actually plays in a given season. Wyers found that for every ball that batters made contact with in 2010, Rogers added .011 home runs, up from a rate of just .002 from 2005 to 2009. That puts Rogers Centre in 2010 among the top 3 percent of home run ballparks since 1950.

But only the Blue Jays, and not their opponents, got a home run boost in Toronto. When the Jays were on the road in 2010, they hit home runs in 4 percent of plate appearances in which they made contact, compared with an AL average of 3.6 percent. At Rogers, their home run on contact rate soared to 5.4 percent, which is a home-field advantage seven times the magnitude teams typically enjoy.

Opposing batters, however, actually homered on contact at a below-average rate in Toronto. As a result, the power differential between home and visiting hitters at Rogers in 2010 was the third largest of any park in any season over the past 60 years (see chart).

[Can_of_corn]

Of course tipping a pitch is legal. It's the pitchers responsibility to have the same pattern/deliver across all pitches!!

I believe with Randy Johnson (1997) he was holding his glove at a different angle when he was throwing his slider?

Nice to see we agree on this.

[T. Legend]

If a pitcher has averaged a certain home run rate over the course of his career (ie: the mean), then without any significant change in circumstances, I would expect him to be right around that number again. Keep in mind that his numbers away from Coors last year (1 home run every 10 innings), were still far worse than his numbers this year.

Also keep in mind that the ballparks he played in most often in the NL West (Dodger Stadium, Petco, AT&T all top 5 pitcher parks in MLB) probably helped his numbers the other way as well.

[Lucky Jim]

If a pitcher has averaged a certain home run rate over the course of his career (ie: the mean), then without any significant change in circumstances, I would expect him to be right around that number again. Keep in mind that his numbers away from Coors last year (1 home run every 10 innings), were still far better than his numbers this year.

Also keep in mind that the ballparks he played in most often in the NL West (Dodger Stadium, Petco, AT&T all top 5 pitcher parks in MLB) probably helped his numbers the other way as well.

Now, by themselves, the above splits aren't conclusive, so to measure the effect of Rogers Centre more precisely, The Mag consulted with Wyers. He has developed a method that generates park factors by comparing a player's performance in any given park with his performance in all other parks, not just in road games for that player. This reduces statistical noise and offers a better estimate of how a park actually plays in a given season. Wyers found that for every ball that batters made contact with in 2010, Rogers added .011 home runs, up from a rate of just .002 from 2005 to 2009. That puts Rogers Centre in 2010 among the top 3 percent of home run ballparks since 1950.

But only the Blue Jays, and not their opponents, got a home run boost in Toronto. When the Jays were on the road in 2010, they hit home runs in 4 percent of plate appearances in which they made contact, compared with an AL average of 3.6 percent. At Rogers, their home run on contact rate soared to 5.4 percent, which is a home-field advantage seven times the magnitude teams typically enjoy.

Opposing batters, however, actually homered on contact at a below-average rate in Toronto. As a result, the power differential between home and visiting hitters at Rogers in 2010 was the third largest of any park in any season over the past 60 years (see chart).

Hammel aside.