Testing Overlays

[JerryBoyle]

Originally Posted by storyline

Almost never have I heard anyone speak or even mention this very real variable (spring, summers vs winter racing) when manipulating databases for modeling.

Do most handicappers ask the right questions when determining which horse to play?

I think if you are basing wagering decisions on past performance of horse and trainer you'll miss cashing tickets when price-horses run new tops which happens everyday at a track near you.

Perhaps handicappers could spend time determining why some horses are ready to run a big race under today's conditions or not.

My (lazy) attempt at handling seasonality is to roll my model recalibration as new races come in. Thinking is that if my model utilizes enough factors, whose relative impact varies by season, recalibrating as we enter the season will shift the weights as appropriately. That backtest was done using a rolling recalibration, so it may not be the best strategy

[storyline]

Originally Posted by JerryBoyle

My (lazy) attempt at handling seasonality is to roll my model recalibration as new races come in. Thinking is that if my model utilizes enough factors, whose relative impact varies by season, recalibrating as we enter the season will shift the weights as appropriately. That backtest was done using a rolling recalibration, so it may not be the best strategy

If I had to choose between "more filtering" or "more testing" I'd pick more filtering everytime.

Garbage in - garbage out.

Not all factors have the same weight/significance for the same horse at all times throughout the year.

Data mining is a slippery slope if someone is entering all the different variables and then trying to gleam meaningful information imo

[Dave Schwartz]

Originally Posted by storyline

Almost never have I heard anyone speak or even mention this very real variable (spring, summers vs winter racing) when manipulating databases for modeling.

Do most handicappers ask the right questions when determining which horse to play?

I think if you are basing wagering decisions on past performance of horse and trainer you'll miss cashing tickets when price-horses run new tops which happens everyday at a track near you.

Perhaps handicappers could spend time determining why some horses are ready to run a big race under today's conditions or not.

Generally, I do not play during the winter. Last November, just before Thanksgiving, I did a live play session (i.e. with an audience) and the racing was just horrible. My handicapping was not so hot, either.

I dedicated several weeks to figuring out just how different winter racing really is.

For over a decade I have used month-of-year in gathering races from the database to build a model of "races like this one." Specifically, +/- 2 months.

But this was different.

The first thing I determined was that racing is "different" from the week before Thanksgiving to around Jan. 21. The races are just far less predictable and/or do not match my handicapping approaches.

Ironically, many of the usual factor values - like recent speed ratings, for example - actually perform BETTER! But somehow the puzzle just doesn't fit together properly; the picture of the winner's circle just does not match the puzzle box.

I THINK... but have no proof of this... that it stems from the trainer patterns changing for the holidays. I THINK that the best trainers simply take time off from racing and hand the reigns over to assistants for about two months. This causes differences.

Very open to other ideas. BTW, it is not just weather because things change even in the warmer climates. (Not as much, but still different.)


Dave

[CincyHorseplayer]

Originally Posted by Dave Schwartz

Generally, I do not play during the winter. Last November, just before Thanksgiving, I did a live play session (i.e. with an audience) and the racing was just horrible. My handicapping was not so hot, either.

I dedicated several weeks to figuring out just how different winter racing really is.

For over a decade I have used month-of-year in gathering races from the database to build a model of "races like this one." Specifically, +/- 2 months.

But this was different.

The first thing I determined was that racing is "different" from the week before Thanksgiving to around Jan. 21. The races are just far less predictable and/or do not match my handicapping approaches.

Ironically, many of the usual factor values - like recent speed ratings, for example - actually perform BETTER! But somehow the puzzle just doesn't fit together properly; the picture of the winner's circle just does not match the puzzle box.

I THINK... but have no proof of this... that it stems from the trainer patterns changing for the holidays. I THINK that the best trainers simply take time off from racing and hand the reigns over to assistants for about two months. This causes differences.

Very open to other ideas. BTW, it is not just weather because things change even in the warmer climates. (Not as much, but still different.)


Dave

I believe bad weather affects the racing. I still might bet Mahoning or Aqueduct in the winter on a fast track but I long ago stopped betting any northern racetracks after the Breeders Cup.

What you mention about trainers I feel is true but for me it's January where I see the most chalk and nonsense results over the years. Everywhere. But I admit that hasn't been true for me the last 2 years betting Fair Grounds, Tampa, and GP.

Other than January for me the worst months are September and November. The pools close in this city and Saratoga is over after Labor day. And unless I am elsewhere the summer is officially over feel leaves me uninspired and I don't do much good handicapping work. Then after the Breeder's Cup and before the winter meets kick off it's much of the same unless I am absolutely itching for action. December 1st is my horseplaying new year so I usually sit this month out in anticipation anyway!

Anyway just piggybacking random thoughts of your post because it reminded me of these things!

[storyline]

Originally Posted by Dave Schwartz

Generally, I do not play during the winter. Last November, just before Thanksgiving, I did a live play session (i.e. with an audience) and the racing was just horrible. My handicapping was not so hot, either.

I dedicated several weeks to figuring out just how different winter racing really is.

For over a decade I have used month-of-year in gathering races from the database to build a model of "races like this one." Specifically, +/- 2 months.

But this was different.

The first thing I determined was that racing is "different" from the week before Thanksgiving to around Jan. 21. The races are just far less predictable and/or do not match my handicapping approaches.

Ironically, many of the usual factor values - like recent speed ratings, for example - actually perform BETTER! But somehow the puzzle just doesn't fit together properly; the picture of the winner's circle just does not match the puzzle box.

I THINK... but have no proof of this... that it stems from the trainer patterns changing for the holidays. I THINK that the best trainers simply take time off from racing and hand the reigns over to assistants for about two months. This causes differences.

Very open to other ideas. BTW, it is not just weather because things change even in the warmer climates. (Not as much, but still different.)


Dave

Lots of things here worth discussing Dave.

A small list of things not captured by simply inputting data

Adjusting for maturity, lasix, barn changes, breeding, jockey changes, equipment changes, quality of competition, how figures were earned, class levels, form, trainer intent, race shape, speed of track, determining false favorites (I'll stop here)

Example to a question that any handicapper might ask - #2 Noble Indy is racing for Pletcher in the La Derby Saturday and is getting blinkers. Statistically Pletcher horses do well in those situations but we're talking about a trainer that does pretty well in all situations (25% win Trainer).

The question that needs to be answered is will Noble Indy move forward, regress or stay about the same because of the equipment change? Pretty important question if you're betting the race imo.

[storyline]

Originally Posted by storyline

Lots of things here worth discussing Dave.

A small list of things not captured by simply inputting data

Adjusting for maturity, lasix, barn changes, breeding, jockey changes, equipment changes, quality of competition, how figures were earned, class levels, form, trainer intent, race shape, speed of track, determining false favorites (I'll stop here)

Example to a question that any handicapper might ask - #2 Noble Indy is racing for Pletcher in the La Derby Saturday and is getting blinkers. Statistically Pletcher horses do well in those situations but we're talking about a trainer that does pretty well in all situations (25% win Trainer).

The question that needs to be answered is will Noble Indy move forward, regress or stay about the same because of the equipment change? Pretty important question if you're betting the race imo.

Now here's the trick, if you can accurately assess that Noble Indy will move forward the next question you might ask is by "how much". Is it enough to dominate this field?

That answer could significantly influence your wagering decision and amount invested.

[Denny]

What's great about 25%?

That means he loses 75%.

Statistics are misused by most.

[storyline]

Originally Posted by Denny

What's great about 25%?

That means he loses 75%.

Statistics are misused by most.

That's what you got from my posts? Amazing.

[Denny]

Thaskalos is right. Knowing ones own psychological makeup is critical.

Not only in dealing with winning and losing, knowing one's own self when handicapping and betting is essential. Unless you're a computer, your decision making is influenced by your present state of mind and beliefs.

[classhandicapper]

Originally Posted by storyline

Almost never have I heard anyone speak or even mention this very real variable (spring, summers vs winter racing) when manipulating databases for modeling.

Do most handicappers ask the right questions when determining which horse to play?

I think if you are basing wagering decisions on past performance of horse and trainer you'll miss cashing tickets when price-horses run new tops which happens everyday at a track near you.

Perhaps handicappers could spend time determining why some horses are ready to run a big race under today's conditions or not.

I think handicappers sort of understand that the game changes seasonally.

For example, the winter in NY is probably the best time to pay attention to trainers that do well off the claim because that's the time of year they can make the most money. There are more opportunities and the trainers with quality stock leave.

At this time of year handicappers in NY are getting ready to deal with a lot of horses shipping up from Florida and possibly other warm areas. It probably makes sense to pay attention to which barns are sending their horses up ready for a peak effort against the weaker NY horses. That's something you won't have to deal with at other meets.

They also know there are going to be a lot more turf horses coming off layoffs because they were turned out and rested during the winter months. The same is even true of many stakes horses that were given 2-3 months off specifically for a freshening.

Personally, I have never tried to change my methods seasonally, but I realize aspects of the game change seasonally and certain strengths or weakness in my own game could be accented by what's important at that time of year.

[Denny]

Originally Posted by storyline

Lots of things here worth discussing Dave.

Example to a question that any handicapper might ask - #2 Noble Indy is racing for Pletcher in the La Derby Saturday and is getting blinkers. Statistically Pletcher horses do well in those situations but we're talking about a trainer that does pretty well in all situations (25% win Trainer).

The question that needs to be answered is will Noble Indy move forward, regress or stay about the same because of the equipment change? Pretty important question if you're betting the race imo.

It was the question you asked. Most of the rest was useless bs to me.

Statistics is a large component of this thread. Though most of them are misinterpreted by most.

That's whats truly "AMAZING"!

[storyline]

Originally Posted by Denny

It was the question you asked. Most of the rest was useless bs to me.

Statistics is a large component of this thread. Though most of them are misinterpreted by most.

That's whats truly "AMAZING"!

That's precisely the point, I'm imploring players to measure the horse more as opposed to measuring statistics more.

[storyline]

Originally Posted by DeltaLover

Getting the average of previous figures is not useful for handicapping and betting reasons. In contrary, in most of the cases such an approach will suppress your chances of catching career best performances, which is where most of the betting interest lies in.

Also using constraints like “same surface” or “same distance” make your process more conservative focusing to an easier to attack problem that is also solved pretty well by the betting crowd. Focusing on more challenging problems, like surface, distance or circuit switches is way more attractive as this is where most of the crowd miscalculations occur.

As far as the second part of your posting, I think you are asking the wrong question. Your best betting selection should not be decided by its ranking (meaning whether is your top selection of the fourth one) but from the possibility of the crowd to misestimate its angles regardless of how its final price will be shaped in the market. The crowd is really good in ABC handicapping so trying to beat it by forming a superior ranking of horses (meaning where your top picks will win more often than the pubic favorite for example) is simply a dream pipe that is impossible to accomplish. The best you can do is to detect the way the public is forming the pools (something that changes constantly through time and also differs from track to track) and try to “correct” any potential mistake before the crowd realize it and encapsulate it to its betting.

Not sure how I missed reading this post which imho is entirely correct, well done Dlover

[JerryBoyle]

Originally Posted by JerryBoyle

My (lazy) attempt at handling seasonality is to roll my model recalibration as new races come in. Thinking is that if my model utilizes enough factors, whose relative impact varies by season, recalibrating as we enter the season will shift the weights as appropriately. That backtest was done using a rolling recalibration, so it may not be the best strategy

Made some modifications and improved my model a bit. The attached chart includes the testing and validation ranges. Clearly the validation range is much better than the previous I posted. Results in general are also much better w.r.t draw downs.

There are man simplifying assumptions made in the backtest which would cause real results to likely be significantly worse. Not sure how many people on the forum are doing much modeling, but I'd be interesting in starting a chat about going from test results to actual live betting.

[acorn54]

to determine if a model exceeds randomness, it must exceed the critical z score of the null hypothesis for the model you are working on.
when you have such a model, assuming you ever do get to that point of development, you use it in real time going forward to see if it continues to exceed randomness, and of course if it produces a profit commensurate with the risk you are taking using said model. that is how you "test overlays"