Downhill Turf course post data @ SA

[AskinHaskin]

Daily Racing Form Retweeted
Marcus Hersh @DRFHersh

"Over time have heard several SoCal horsemen refer to post bias against inside on downhill turf course at SA but stats don't bear that out."


I dunno about that statement.


Here is the raw data:


Since the start of 2000:



1 182- 1815(.10)
2 188- 1815(.10)
3 208- 1815(.11)
4 204- 1815(.11)
5 213- 1811(.12)
6 224- 1759(.13)
7 201- 1598(.13)
8 129- 1343(.10)
9 112- 1050(.11)
10 89- 766(.12)
11 52- 433(.12)
12 18- 214(.08)
13 0- 11(.00)
14 0- 6(.00)


Were you to rank the oft-used posts in order of success, #1 and #2 would each be near the bottom. That even though all post stats are flawed in favor OF the very inside posts. This because #11 never gets to run without a maximum 9% natural chance of success, while #1 and #2 got to run 56 times with at least a 20% natural chance of success and 217 times with at least a 16% natural chance of success.

Geez, #6 has 23% more wins than #1 even though it has 56 fewer starts.

[Richie]

I think its worse when the field size is 10 or 11 plus

[Robert Fischer]

I'm not an expert at Santa Anita.

Pretty sure the rail comes out to put inside posts in tight.

[cj]

You have to account for field size. For example, a 12 post always has to beat at least 11 other horses, maybe more. A 1 post might only have to beat one other horse.I did this the last time the BC was held at Santa Anita and the inside is definitely at a disadvantage.

[ReplayRandall]

You have to account for field size. For example, a 12 post always has to beat at least 11 other horses, maybe more. A 1 post might only have to beat one other horse.I did this the last time the BC was held at Santa Anita and the inside is definitely at a disadvantage.

The OP is talking about the downhill course, which favors outside speed because of the outer-rail first bend "to the right" configuration being the shortest distance.

[cj]

The OP is talking about the downhill course, which favors outside speed because of the outer-rail first bend "to the right" configuration being the shortest distance.

I was too, sorry I wasn't clearer.

[Robert Fischer]

Since the start of 2000:



1 182- 1815(.10)
2 188- 1815(.10)
3 208- 1815(.11)
4 204- 1815(.11)
5 213- 1811(.12)
6 224- 1759(.13)
7 201- 1598(.13)
8 129- 1343(.10)
9 112- 1050(.11)
10 89- 766(.12)
11 52- 433(.12)
12 18- 214(.08)
13 0- 11(.00)
14 0- 6(.00)

.

Using CJ's logic, and looking at these numbers...
Looks like we can pretty much say that all of these races had at least five horses (only off by 4/1815). In other words a minimum field at five.

We can see with posts three, four, five - A trend towards an outside bias.

After post five, we have to allow for natural odds increase.

Without Busting my brain, the gist = posts 5-11 are the place to be.

Inside 5 can be bad , outside 11 are inconclusive

[DeltaLover]

Using CJ's logic, and looking at these numbers...
Looks like we can pretty much say that all of these races had at least five horses (only off by 4/1815). In other words a minimum field at five.

We can see with posts three, four, five - A trend towards an outside bias.

After post five, we have to allow for natural odds increase.

Without Busting my brain, the gist = posts 5-11 are the place to be.

Inside 5 can be bad , outside 11 are inconclusive

Based on these data I do not think that the post position has a significant impact neither from the outcome of the race nor from a ROI scope of view.

http://i66.tinypic.com/de419v.png

[Robert Fischer]

Good stuff.

Trying to interpret data like this is kind of an art in its own right.

[VigorsTheGrey]

I don't quite understand the point of post position stats for the simple reason that once the gate opens, the horses quickly rearrange themselves into other positions to do the majority of the running...it is not like they stay in that path the whole way around...most outside speed quickly drops more inside for the running and most tardy breakers do the same thing, so what's the point?

[SoCalCircuit]

I'd be curious on average how much more (if any) ground the inside posts have to cover. That could make the difference given these races are nearly always within a length or two.

[DeltaLover]

I'd be curious on average how much more (if any) ground the inside posts have to cover. That could make the difference given these races are nearly always within a length or two.

How this will help you more than the macro-statistics that model the behavior of the post positions? I believe that as a handicapper you should try to reach your conclusions based on abstractions and generalities rather than details and micro-views. In other words you must not try to discover why something is happening and be happy only if you are able to detect it.

[SoCalCircuit]

What? I was just curious if anyone had data on feet traveled inside posts versus outside posts. It's a unique scenario because there's both a left and right turn, and I think total feet traveled is a handicapping angle...

[ReplayRandall]

Based on these data I do not think that the post position has a significant impact neither from the outcome of the race nor from a ROI scope of view.

http://i66.tinypic.com/de419v.png

You have to break this down much more. It requires extensive work by going back to PP's of each race down the hill, filter for outside speed first, layer for the number of entrants, as well as layering for the odds. Outside speed is dominant with the downhill course at SA. Those who have no speed in the outside posts are at a distinct disadvantage.....

[DeltaLover]

You have to break this down much more. It requires extensive work by going back to PP's of each race down the hill, filter for outside speed first, layer for the number of entrants, as well as layering for the odds. Outside speed is dominant with the downhill course at SA. Those who have no speed in the outside posts are at a distinct disadvantage.....

Do you have any data to support what you are saying here or it is just an opinion based on experience?

[ReplayRandall]

Do you have any data to support what you are saying here or it is just an opinion based on experience?

Sent you a PM...

[cj]

Based on these data I do not think that the post position has a significant impact neither from the outcome of the race nor from a ROI scope of view.

http://i66.tinypic.com/de419v.png

If that image is correct, and I'm not doubting it, I have no idea how you could draw that conclusion. Outside is clearly an advantage down the hill both in my experience and in the data you posted (and the data I have myself)

[cj]

I'd be curious on average how much more (if any) ground the inside posts have to cover. That could make the difference given these races are nearly always within a length or two.

Why would the inside posts cover more ground? I know it is a unique layout but there is no logic to thinking the 1 horse would cover more than the outside horses even given the course they run over.

[VigorsTheGrey]

I've talked about this before that due to the layout of the course, the inside posts are forced to send hard or agree to take back early...this can compromise their chances if sending is not their preferred running style.

The fields momentum is to move collectively in a straight line, which causes a pinching effect for horses drawn inside at the right hand turn point in the race. Many horses drawn inside must drop back or send hard to avoid being shut off by horses drawn outside that are not quite moving rightward enough to allow room for all the horses to race evenly....the horses drawn outside can race to their preferred style but the closers drawn inside must wait for a hole to appear after they cross the dirt strip....most times the hole does open as railbirds tend to drift out toward the middle of the grass stretch at this point in the race but closers will often choose to go around instead yet come to flatten out later on. The race is usually won by an e/p or p type from just off the pace drawn favorable middle/ middle/outside post position.

[SoCalCircuit]

Here's a decent example of what I was thinking:

https://m.youtube.com/watch?v=lR5bCKJzZZU

Reneesgotzip :1: and No Nay Never :13: had literally the exact same trip, except Renee had to clear the entire field and cover more ground.

[cj]

Here's a decent example of what I was thinking:

https://m.youtube.com/watch?v=lR5bCKJzZZU

Reneesgotzip :1: and No Nay Never :13: had literally the exact same trip, except Renee had to clear the entire field and cover more ground.

Watching the replay I doubt Trakus would say the 1 covered more ground, but since Trakus is down right now I can't check...will in the morning.

[SoCalCircuit]

Would appreciate that CJ. I could be way way off here, just a vague instinct I've had over watching many races over the hill all these years to possibly explain the post position stats.

[AskinHaskin]

So assuming that other data is a smaller, more recent window of the hillside course (never really confirmed here)...


The first thing to do is to cross-check the earlier window of time as so:


1 146 - 1460 (10.000%)
2 146- 1460 (10.000%)
3 170 - 1460 (11.64%)
4 161 - 1460 (11.027%)
5 178 - 1458 (12.208%)
6 181 - 1406 (12.8733%)
7 159 - 1271 (12.5098%)
8 104 - 1076 ( 9.6654%)
9 87 - 844 (10.308%)
10 73 - 618 (11.812%)
11 46 - 357 (12.885%)
12 16 - 182 ( 8.7912%)
13 0 - 10
14 0 - 5


And from that, one would have to be clueless to suggest that the original horsemen's belief that the course does not favor the inside couple of posts is not supported by reality.


LOL - the 11 hole, with never more than a 9.09...% chance of winning, won at a significantly greater percentage than did the inside two slots, despite the inside pair having all of the numerical advantages relating to being sometimes a 1-in-5 chance or a 1-in-6 chance.


And the natural rankings by percentage of wins, in that earlier subset of all races in the 2000's run at 6 1/2 down the SA hillside, are as such:

11-6-7-5-10-3-4-9-1-2-8-12


That while the 1-through-6 slots should be expected to have a stranglehold on being the best percentage posts, for reasons of field size alone.


So back to the original concern:

What is Marcus Hersh thinking?

[upthecreek]

9/30--10/30

[DeltaLover]

If that image is correct, and I'm not doubting it, I have no idea how you could draw that conclusion. Outside is clearly an advantage down the hill both in my experience and in the data you posted (and the data I have myself)

I believe that the data are correct albeit not complete as they contain some gaps and are missing some races. Any way I do no really see how they can be interpreted to reveal some kind of bias. When I will have the time I might pass them to a ChiSquare test to see if I am wrong.

[Robert Fischer]

For starters, we have to remember that we have more information than the 355 race 'snap shot'.

It's pretty clear that the #2Post is not a leader among win% over other larger samples, as in that particular 'snap shot' of data.

In other words, that particular 355 race sample had an unusual amount of winners at the #2 post which is not representative of what the larger samples are showing from the #2 post.

Draw a line through the 2 post in the 355 race sample with the ROI.


Once you do that, the 'ROI' in that sample agree with the 'win%' of the larger samples.
After post 4, we see a significant ROI increase.


The question that we get from the 355 race sample is not about disputing the commonly held belief of the inside bias(rather, it helps confirm it), it's whether the #8POST perhaps also has some significant bias.
All 3 samples show a significant decrease in win% and ROI for exactly the #8POST.
I don't know whether this was randomness, or if it is saying that when there are exactly 8 runners, the 8Post has a disadvantage. Something to think about. While the 8POST outperforms the bad inside posts in terms of natural odds (and probably ROI as well in the larger samples), the data on POST#8 is interesting enough to consider.

Ultimately we aim to interpret the data. We note significant bias. We try to comprehend why that bias occurs through actual visual insight into the track configuration and race dynamics. We try to apply that insight to better understand the significance of the bias regarding general post postions, and also specific horses with varying pace/running styles.



A)
1 182- 1815(.10)
2 188- 1815(.10)
3 208- 1815(.11)
4 204- 1815(.11)
5 213- 1811(.12)
6 224- 1759(.13)
7 201- 1598(.13)
8 129- 1343(.10)
9 112- 1050(.11)
10 89- 766(.12)
11 52- 433(.12)
12 18- 214(.08)
13 0- 11(.00)
14 0- 6(.00)

B)
1 146 - 1460 (10.000%)
2 146- 1460 (10.000%)
3 170 - 1460 (11.64%)
4 161 - 1460 (11.027%)
5 178 - 1458 (12.208%)
6 181 - 1406 (12.8733%)
7 159 - 1271 (12.5098%)
8 104 - 1076 ( 9.6654%)
9 87 - 844 (10.308%)
10 73 - 618 (11.812%)
11 46 - 357 (12.885%)
12 16 - 182 ( 8.7912%)
13 0 - 10
14 0 - 5


C)
http://i66.tinypic.com/de419v.png

[rsetup]

They must run in mandatory lanes out there. No other way to make sense of the nonsense in this thread.

[cj]

Would appreciate that CJ. I could be way way off here, just a vague instinct I've had over watching many races over the hill all these years to possibly explain the post position stats.

The 1 ran 23 fewer feet in that race you mentioned than the 13 did according to Trakus.

[ReplayRandall]

We've been through this before with raw data %'s. You must follow through with the rest of the filtering. Show the data for just fields of 8, down the hill, and continue with just 9,10,11 and 12. Now look at what the data says, and then you must add more filtering for speed in the outside posts, which requires work sifting through the PP's.....It takes work, as there are NO shortcuts. Trust me, if you do the work, you'll find "it".

[SoCalCircuit]

The 1 ran 23 fewer feet in that race you mentioned than the 13 did according to Trakus.

Thanks. I stand 100% corrected.

[cj]

Thanks. I stand 100% corrected.

No worries, this is how we learn things! I'm wrong plenty :)

[Robert Fischer]

~18seconds makes a right-hand turn
~32seconds in very tight to the left-hand rail.
http://oi66.tinypic.com/2u7yc1f.jpg

Inside posts must either use horse to lead the pack, or be in tight on the left hand rail.


red silks leader in graphic post1RENEESGOTZIP quicklysprinted clear, set the pace along the inside, hopped onto the dirt crossing, drifted out despite right handed pressure in the stretch and weakened.


If you count horses who are along the rail in the 2nd(right) picture the horse who is 4th back along the rail white/blue looking silks, perhaps 7th overall =
post2SILENTIO squeezed at the start, went up inside to chase the pace, continued inside into the stretch and weakened.

[VigorsTheGrey]

~18seconds makes a right-hand turn
~32seconds in very tight to the left-hand rail.
http://oi66.tinypic.com/2u7yc1f.jpg

Inside posts must either use horse to lead the pack, or be in tight on the left hand rail.


red silks leader in graphic post1RENEESGOTZIP quicklysprinted clear, set the pace along the inside, hopped onto the dirt crossing, drifted out despite right handed pressure in the stretch and weakened.


If you count horses who are along the rail in the 2nd(right) picture the horse who is 4th back along the rail white/blue looking silks, perhaps 7th overall =
post2SILENTIO squeezed at the start, went up inside to chase the pace, continued inside into the stretch and weakened.


Your post here pretty much says what I said in post 19...there is another advantage to having a middle or outside post, that is, on right turns the outside IS the inside for THAT TURN, and the outside and the middle posts gets clear sailing each turn, right or left...

[AskinHaskin]

Great... so NOW we have #1 traveling fewer feet than #13, AND #1 having all of the usual advantages known to inside posts in the eternally-flawed post position stats as always offered in racing...

Yet STILL the inside pair are in arrears vs most other posts.


So one need not do any real further research to see that Marcus Hersh makes no sense at all with his tweet.


Curiously, and perhaps unique to this turf course, the 'inside'-most post could be in a vast array of different gate stalls based on field size.

For this isn't a mere question of not using the innermost stall as some tracks do(n't), with less-than-full gates. They can put'em anywhere they like when fields are compact in size.

[ReplayRandall]

Great... so NOW we have #1 traveling fewer feet than #13, AND #1 having all of the usual advantages known to inside posts in the eternally-flawed post position stats as always offered in racing...

Yet STILL the inside pair are in arrears vs most other posts.


So one need not do any real further research to see that Marcus Hersh makes no sense at all with his tweet.


Curiously, and perhaps unique to this turf course, the 'inside'-most post could be in a vast array of different gate stalls based on field size.

For this isn't a mere question of not using the innermost stall as some tracks do(n't), with less-than-full gates. They can put'em anywhere they like when fields are compact in size.

Yep, I think you got it now....

[theiman]

In 10 horse fields or less, I believe, the #1 post starts from Gate #4. Thus leaving empty gates for 1, 2, 3 & 14.

As the field gets bigger they start using the first three gates and the 14 gate, as needed.

Thus one may want to look at stats, if available, on how the inside has fared with 10 horses, or less, vs how the inside posts have fared with more than 10 horse fields.

[VigorsTheGrey]

In 10 horse fields or less, I believe, the #1 post starts from Gate #4. Thus leaving empty gates for 1, 2, 3 & 14.

As the field gets bigger they start using the first three gates and the 14 gate, as needed.

Thus one may want to look at stats, if available, on how the inside has fared with 10 horses, or less, vs how the inside posts have fared with more than 10 horse fields.
This makes some sense but make the search parameters 7 or less, and 8 and more....what do you think about that?

[Lemon Drop Husker]

In a BC race down the hill with an almost for sure 14 horse field, in a major pressure packed race with nerves at their highest....; yeah I'll be looking for a closer and a solid jock coming into :43 and change fractions....

I like it A Lot and may be Amibtiously Brew'ing a few back.

The stats that mean something to me in the BC Turf Sprint are the 5 winners from before at this very venue:

'08 Desert Code (The Mig) came from 12th to 1st out of the 9 hole with solid SA experience.

'09 - California Flag (Talamo) simply wired the field from the 3 hole and got it done. Serious SA experience.

'12 - Mizdirection (Mike Smith) came out of the 12 hole, was "chalky", in the mix early in a stalking position, and got it done. SA veteran.

'13 - Mizdirection (Mike Smith) came out of the 11 hole, not "chalk", and rolled from 11th to 1st. SA back-to-back vet.

'14 - Bobby's Kitten- (Rosario) Rolled from dead last to get it done, zero SA experience before.

Pretty tough to take someone on the front end at SA in the BC Turf Sprint down the hill IMO. Maybe the more important trick is to find a patient jock sitting on a closer, to likely even deep closer, with a post middle to outside.