How people bet.

[flatstats]

ROI is not the best metric. It can be flawed due to a rogue huge priced winner. If a jockey randomly wins on a 100/1 shot then the ROI can be positive for a couple of years.

Use the IV at the very least but ideally the A/E is the stat to use. This will take into consideration the odds of the horse and thus compensates for field sizes, trainer, owner, breeding, and mass public popularity.

In the UK some media pundits swear by jockey Ryan Moore and consider him to be an outstanding jockey. But for betting purposes he does not even rank in the top 100 of value jockeys (based on A/E)

Another issue with jockey stats is that punters only look at the overall stats. They see the all time performance but should be looking at individual courses and race conditions.

This is not much of an issue in the US but it is a big issue in the UK. We have 40 courses that any jockey can ride at and some ride at two meetings in the same day. As UK courses are so disparate then jockey ability can be different at each course.

e.g. A Jockey may be good on a flat surfaced, galloping left hand track but perform badly on a right handed, undulating stiff track.

In the US your courses are more uniform but you will get jockey biases for different going allowances (on turf UK ranges from Heavy to Firm) and for different distances such as sprints, middle route.

The vast majority of punters assume a jockey is a machine that is just there to steer the horse. This is not true and all jockeys exhibit flaws and biases of some kind. But you will never know that unless you use the A/E stat.

[Grits]

Originally Posted by BettinBilly

"In the Preakness, The horse broke dead last again. Then after a Furlong, Turcotte grabbed a hold of him and made an almost imperceptible gesture like a man adjusting his cuff. The horse took off and went from last to first in 100 yards."

Since reading that I've been looking for verification of the significance of this "almost imperceptible gesture". Lucien Lauren states he told Turcotte to let him go and run his own race. Penny Tweedy stated that Turcotte would not have driven the horse to break for the lead that early in the race, and that it had to be something the horse wanted to do.

http://www.horseracingpics.com/secpr...gnedphoto2.jpg

"Secretariat begins his sensational looping rush" -- as Raymie Woolfe Jr's caption reads in his most famous photo of him in the Preakness.

--From, "Secretariat". (One of my many coffee table horse books, and my favorite photo of him.)

[BettinBilly]

Originally Posted by Grits

http://www.horseracingpics.com/secpr...gnedphoto2.jpg

"Secretariat begins his sensational looping rush" -- as Raymie Woolfe Jr's caption reads in his most famous photo of him in the Preakness.

--From, "Secretariat". (One of my many coffee table horse books, and my favorite photo of him.)

You got my vote, Grits. I even have it on my Kindle. Awesome Photo. Thank you.

[mishka]

I try to note changes for the given race such as change in class, distance, etc. A jockey change is on the list--one among other factors.

Hopefully not too off topic, but I wonder if the comments on previous races in past performances can reveal some insights when a trainer uses the the same jockey. For example, sometimes comments will show that a horse goes wide (4w,5w, 6w) a lot. Is this a function of the jockey not timing a move properly??

[Tall One]

Originally Posted by Hoofless_Wonder

Back in the day, once glance at the tote board could tell you who Pat Day was riding at Churchill, Oaklawn or Arlington.

Aint that the truth. It was even worse out here at Keeneland. And to an extent Keeneland is notorious for fans driving prices down on whichever mount the hot jock or apprentice was on. Willy Martinez, Fabio Arguello, jr..Wigberto Ramos..

But, those early '90s summer jockey colonies Arlington had back then were stout: Day, Jorge Velasquez, Mike Smith before he went to NY full time, Romero, Earlie Fires, Guidry, an up and coming Shane Sellers, plus a solid group of local riders.

But, you could catch Day on 10 or 15-1 shots up at the Spa, and make up for the short prices.

[EMD4ME]

Originally Posted by Grits

Thask, he was rare, indeed. I think his name's ... Ramon.

Miss him. Still.

Amen. All jockeys can only blow a race with their idiotic rides.

Ramon is the only jockey that I have ever seen that can help a mule win & can make a "sure thing" a mortal blanken LOCK.

I miss his professionalism, preparation, mental aptitude, soft hands, humility and intelligence IMMENSELY.

[cashmachine]

Originally Posted by flatstats

Use the IV at the very least but ideally the A/E is the stat to use.

What is "IV" and "A/E"? How do you compute them?

[IrishRail76]

Originally Posted by EMD4ME

Amen. All jockeys can only blow a race with their idiotic rides.

Ramon is the only jockey that I have ever seen that can help a mule win & can make a "sure thing" a mortal blanken LOCK.

I miss his professionalism, preparation, mental aptitude, soft hands, humility and intelligence IMMENSELY.

You and Grits are 100% spot on. Plus, Ramon made it look sooo easy.

I didn't see any mention of "longshot specialists" in the thread, but we've all got our favorite "go to" super saver. From 2000 - 2010, mine was Omar Berrio (So Cal). I know that he suffered two strokes a few years ago and left for awhile, so I hope this finds him in better health.

[flatstats]

IV - Impact Value
This is a figure, which takes into consideration the number of starters as well as the number of winners in a group. It can indicate if there is a bias towards a particular group or not.

e.g. in a specific Maiden Stakes race (UK) the genders that win a race may look like this:

Total Races 786
Colts won 188
Fillies won 361
Geldings won 268
Mares won 6

From that you may think fillies are the best horses to follow as they won 361 of the 786 races. But what you don't know is how many starters in each group there were. What if 500 fillies raced, or 5000?

Some use the strike rate or Win% but that is flawed for the same reason as you don't know the number of starters. That's where the Impact Value comes in.

Colts 1.64 IV
Fillies 0.93
Geldings 0.89
Mares won 0.28

That is a much better picture on what gender wins these races. It is clear that colts are way better than the other genders.

IVs were pioneered / championed by Fred Davis in his book "Percentages and Probabilities" and then championed by William Quirin, Mike Nunamaker and others. If you search for those you can see the easy formula that is used to calc the figures.

A/E - Actual Winners / Expected Winners
The problem with IV is that it only explains if a group win more or less than their fair share of races. This is not ideal as there is no way of knowing if the general public over or underbet that group. It has no price element and thus it is not possible to work out value. That's where the A/E comes in.

A/E is the actual number of wins divided by the expected number of wins. This is great as we can instantly see if a stat is over or underbet.

The expected number of wins is based on the sum of the odds chance of winning. If you have 10 horses that go off at evens then odds chance of one horse winning =10 * 0.5

odds chance = 1 / (price + 1)
10 horses at evens = 5

Thus with 10 evens priced horses we would expect 5 of them to win. Now look at the actual number of winners.

If the actual number of winners was 6 the A/E = 6/5 = 1.2

That indicates the stat is doing better than expected, or that the public are underbetting the stat (an overlay).

If the actual number of winners was only 4 the A/E = 4/5 = 0.8

This indicates the stat is doing worse than expected, or that the public tend to overbet the stat.

A/E is used by Gordon Pine / Netcapper.

[cashmachine]

Thank you!

[ultracapper]

Originally Posted by IrishRail76

You and Grits are 100% spot on. Plus, Ramon made it look sooo easy.

I didn't see any mention of "longshot specialists" in the thread, but we've all got our favorite "go to" super saver. From 2000 - 2010, mine was Omar Berrio (So Cal). I know that he suffered two strokes a few years ago and left for awhile, so I hope this finds him in better health.

He teamed up with AC Avila for many of those, and Avila had given him a lot of chances the past month or so, but he's not riding well. Obviously, he's healthy, but he's not the same jock. He has actually looked awful a couple times. Almost like he wasn't strong enough to really man handle the horse in the stretch when needed. He had one swimming all over the home stretch a couple weeks ago. Avila went to another jock this weekend, and got his first winner home of the year. I'm sure Berrio just getting back on a horse is an incredible accomplishment, but it's hard to back him with anything but "I'm rooting for you" money.