Home Court Advantage on Dirt?

[Fairmount1]

The last four SA Breeders Cups with Dirt races (Not Synthetic) totaled 29 Dirt Races from \'03, \'12, \'13, \'14.  

Where did they run last?  And how did California trainers do with the home court advantage?  Certainly a home court advantage is to be expected but after the Mandella massacre in\'03, it is not as exaggerated as one would think.  It certainly is not as pronounced as the Euro angle in Turf Routes at SA but still worth thinking about.  

The Archives are just invaluable if you are into researching these issues.  I\'m almost ready to start looking at this year\'s pre-entries.  


29 Dirt Races, Track of the winner\'s previous race:

Santa Anita, 12/29
Del Mar, 2/29
Bel, 5/29
Kee, 4/29
Parx, 3/29
Turfway, 1/29
Europe, 1/29
South America, 1/29

CALIFORNIA as a whole including SA and Del Mar was 14/29 PLUS She\'s A Tiger (SA prev race) was DQ\'ed (and Bel Rio Antonio was put up) so crossing the wire first, the maximum percentage to be considered would be:

15/29=51.7%

Removing the 2003 results from this CA stat and removing the DQ, the percentage is:

10/24=41.7%

So, the home field advantage of a previous race in California (such as East Coast trainer Ritvo used for the Classic in \'13) is still a noteworthy consideration.  

______________________

Trainers of the Dirt BC Races at SA since \'03, California Based Trainers vs. All Others (Only 5 California Trainers have won BC Dirt races out there which is a bit surprising).  

Mandella, 5
Baffert, 3
O\'Neill, 2
Hofmans, 1
Desormeaux, 1

12/29=41.4%

ALL OTHERS 17/29=58.6%

This stat is tough for me to interpret anything meaningful from for use in this year\'s BC.  Maybe an ever so slight nod to Cali trainers but not really something that will necessarily sway me.  Curious Rocky\'s thoughts on this and if this would matter to him whatsoever.  

Best of luck!

[jma11473]

Of course the missing stat is how many of the RUNNERS last ran at what track (or what state, in this case). If 41% of the dirt winners last ran in CA but 36% of all runners last ran in CA, that\'s not a huge difference. Running last in CA does seem to help but without the other half of the equation we don\'t know how much. Thanks for the research though.

[TGJB]

I\'m going to be covering this stuff in detail in the seminar.

Meanwhile, as we get closer, if someone wants to set up a chart by showing when horses get in and where they\'re coming from, that would be really productive.

We got the answer on Run Happy, anybody know where Effinex was stabled before he went out in March?

[FrankD.]

◗ Since arriving from Florida on March 3 with assistant Kent Sweezy, Effinex has looked great physically. He posted a fast half-mile workout Tuesday under jockey Mike Smith, who won the last three Big Caps with Shared Belief in 2015 and Game On Dude in 2013-14.

◗ Jerkens is confident that Effinex will fire despite the layoff of more than three months. "He's a little different horse," Jerkens said. "He doesn't 'belly down' and get heavy. And the track being glib and fast will help."

◗ Effinex has won seven races and more than $2.1 million from 20 starts. His five starts at a 1 1/4 miles produced two wins, a second, and a third.

[TheBull]

Great work. To me, what I would find most relevant is how that compares to other BC\'s at other venues.....for instance home track advantage for a Belmont BC etc? Sadly I do not have such time on my hands. But the comparison would help put those stats into perspective

[Caradoc]

If the DRF is to be trusted, Effinex had been at Palm Meadows since no later than February 4th, when he breezed a half-mile at PmM.  He then worked more or less weekly at PmM before the half breeze that Frank noted at SA on 3/8, four days before the Big Cap.

[paniolo]

Is this type of data useful(time on my hands)?
BC Juvies Colts Dirt
 
Year       #runners    last race @SA    Winner fm SA Last Race                                  
 
2014          11          2                 YES

2013          13          4                 NO

2012           9          4                 NO

Note Only 1 of 10 SA runners hit the board.

Samilar Data can be mined for all BC dirt races for above years

[Fairmount1]

jma11473 wrote: Of course the missing stat is how many of the RUNNERS last ran at what track (or what state, in this case). If 41% of the dirt winners last ran in CA but 36% of all runners last ran in CA, that\'s not a huge difference. Running last in CA does seem to help but without the other half of the equation we don\'t know how much.
_____________________________________________


I was curious the same thing as I was punching out those numbers last night.  And JB said he would cover much of this so hopefully I\'m not stepping on his toes but here you go. Again, if there are errors, my apologies but I\'ve done the best I could in a short amount of time.  Feel free to correct if there is anything wrong.  Thanks.  

There were 311 horses in those 29 Dirt races in \'03, \'12, \'13, and \'14.  

Track of the winner\'s previous race, % of winners, % of runners:

Santa Anita, 12/29.  41.3% of winners.  88/311 RUNNERS, 28.29%
    **SA with She\'s A Tiger, 13/29, 44.8% of horses that crossed the wire first**

Del Mar, 2/29.  6.89% of winners.  10/311 RUNNERS, 3.21%.

Bel, 5/29.  17.2% of winners.  72/311 RUNNERS, 23.1%.
    **Bel without Rio Antonio, 4/29, 13.8%**

Kee, 4/29.  13.8% of winners.  41/311 RUNNERS, 13.1%.

Parx, 3/29.  10.3% of winners.  19/311 RUNNERS, 6.1%.

Turfway, 1/29.  3.44% of winners.  4/311 RUNNERS.  1.2%.

Europe, 1/29.  3.44% of winners.  10/311 RUNNERS (I believe).  3.21%.

South America, 1/29.  3.44% of winners.  5/311 (I believe).  1.6%.  


I have not included the percentages from the many, many tracks that produced no winners including Churchill (0 for 9) and Saratoga (0 for 12) and all the rest.

Some of the obscure Euro and South America letters/symbols may have those two stats for RUNNERS off a tiny bit.  

As for total horses with a previous race in the state of California versus the number of horses that crossed the wire first that previously raced in California.

SA, 88/311.
Dmr, 10/311.
Fresno, 2/311.
Hol, 2/311.
Fairplex, 1/311.  

TOTAL NUMBER OF RUNNERS WITH PREV. RACE IN CALI BEFORE SA BC DIRT RACE, 103/311, 33.1%

PERCENTAGE OF HORSES THAT CROSSED THE WIRE FIRST FROM A PREV. RACE IN CALI, 15/29, 51.7% (Includes DQ\'ed She\'s A Tiger).

Alright, I\'m officially finished with these projects.  I wondered also about how other BC locations would compare to this one for percentage of winners from which tracks but that is an extraordinary undertaking.  

Note the Keeneland comparison nearly identical despite a notion that Keeneland is an advantageous place to ship from into SA.  Also note if you combine Keeneland and Belmont percentages, you have a higher percentage of starters than SA and a lower  percentage of winners than SA. Best of luck and hope this helps confirm a potential home court advantage.

[Fairmount1]

Updating this a bit with last year\'s winners included.  I didn\'t calculate in the total number of runners from each of these tracks like last year due to time constraints but thought I would still share.  Given the BC is at Del Mar for the first time, this may not be helpful to you; others may think it is very helpful.  That\'s for you to decide.  

Percentage of BC Dirt Races that a horse Crossed the Wire First from a Prev Race in Cali in \'03, \'12, \'13, \'14, and \'16 Breeders Cups (all held at SA).    17/36, 47.2%.Includes DQ-ed She\'s A Tiger

Santa Anita, 14/36.  38.8% of winners previous race at SA.

Del Mar, 3/36.  8.3% of winners.

Bel, 6/36.  16.7% of winners.

Kee, 5/36.  13.8% of winners.

Parx, 3/36.  8.3% of winners.

Saratoga, 2/36.  5.5% of winners.

Turfway, 1/36.  2.7% of winners.

Europe, 1/36.  2.7% of winners.

South America, 1/36.  2.7% of winners.  

Interestingly the \"California\" home court advantage by percentage went down despite five of the seven dirt winners being trained by the likes of Baffert, Mandella, Eurton, and Kruljac.  Of course, that\'s because Drefrong and Arrogate both ran previously on Travers Day at Saratoga.....a day I will never forget albeit in a fuzzy, hung over manner sitting next to Uncle Bill.  

More interesting is that the layoffs of these dirt winners were as follows:

Tamarkuz.  Bel. 26 day layoff.
Beholder.  SA.  33 day layoff.
Champagne Room.  SA.  34 day layoff.
Drefong.  Sar.  69 day layoff.
Classic Empire.  Kee.  27 day layoff.
Finest City.  DMR.  61 day layoff.
Arrogate.  Sar.  69 day layoff.  

And thus the long layoff trend by several trainers into the BC began in 2017.  Also noteworthy that ZERO previous dirt BC race winners from Saratoga in those 4 previous SA Breeders Cups.  Then 2 last year from Baffert at SA.  

Wondering if TG seminar will include any stats on long layoffs into the big BC days and the figures those horses have earned given that trend this year.

[Mathcapper]

Rich â€" good stuff, you’re absolutely on the right track in determining whether there really is a home court advantage.

When you compare the percentage of winners to the percentage of runners as you’ve done, you’re measuring what’s called the “impact value”. In its raw form, it’s a good metric, although it can be prone to misleading results because it doesn’t take into account each horse’s actual probability of winning (odds). What\'s even better to use is what’s called an odds-based impact value: Odds-Based Impact Value = Actual Win% / Expected Win %

I posted about just this topic a few years ago in which I included a link to a great little article written by Gordon Pine that’s definitely worth checking out:

Impact Values

As you can see from the results you generated, which on the surface look to show a rather pronounced California bias, impact values (and particularly odd-based impact values) are a powerful tool to help determine if a particular factor or angle is winning at an outsized rate. I use the runstyle and post bias impact factors listed at the back of each race’s Brisnet PP’s regularly to see if there are any biases associated with that particular track profile (even though they’re of the inferior raw form, they’re still quite useful).