Many people bet based on headlines or hunches. I dig into research and market moves behind political odds & manager markets, so you can back decisions, not guesses.
The initial odds you look at on a horse race are an intro into their opinion on a race.
The bookies calculate the chances of each horse winning or placing and initially price up the market so they can profit however the race finishes.
Bookmakers then adjust their prices/odds to increase or maintain their percentage profit.
This is really the essence of bookmaking, the bookies price up individual events guaranteeing themselves a profit whatever the outcome of the individual event
The bookmakers ALWAYS factor in a profit margin, this is known as the overround.
In the 8 runner race example that profit margin is 63.82%
| Selection | Runner | Odds | % |
|---|---|---|---|
| Horse | A | 4/5 | 55.5% |
| Horse | B | 5/2 | 28.5% |
| Horse | C | 3/1 | 25.0% |
| Horse | D | 9/2 | 18.2% |
| Horse | E | 6/1 | 14.3% |
| Horse | F | 7/1 | 12.5% |
| Horse | G | 16/1 | 10.0% |
| Horse | H | 25/1 | 9.1% |
| 163.82% Overround |
The true odds of an 8 runner race should be 7/1 giving each horse a 12.5% chance of winning... but you will never see these odds from a bookmaker because there is no profit for them!
| Selection | Runner | Odds | % |
|---|---|---|---|
| Horse | A | 7/1 | 12.5% |
| Horse | B | 7/1 | 12.5% |
| Horse | C | 7/1 | 12.5% |
| Horse | D | 7/1 | 12.5% |
| Horse | E | 7/1 | 12.5% |
| Horse | F | 7/1 | 12.5% |
| Horse | G | 7/1 | 12.5% |
| Horse | H | 7/1 | 12.5% |
| 100% Overround |
In this 5 runner race example the profit margin is 10.00%.
| Selection | Runner | Odds | % |
|---|---|---|---|
| Horse | A: | 4/5 | 55.50% |
| Horse | B: | 5/2 | 28.50% |
| Horse | C: | 7/1 | 12.50% |
| Horse | D: | 11/1 | 8.50% |
| Horse | E: | 20/1 | 5.00% |
| 110.% Overround |
Punters need to always understand these margins especially when horses are talked about being heavily backed or drifting like a barge.
How Bookmakers Work and Create Odds
Odds On Prices And Percentages
| Fractional Prices - Odds On | Percentage |
|---|---|
| 1/10 | 90.91% |
| 1/9 | 90.00% |
| 1/8 | 88.79% |
| 1/7 | 87.50% |
| 1/6 | 85.71% |
| 2/11 | 84.62% |
| 1/5 | 83.33% |
| 2/9 | 81.82% |
| 1/4 | 80.00% |
| 2/7 | 77.78% |
| 3/10 | 79.62% |
| 1/3 | 75.00% |
| 4/11 | 73.33% |
| 2/5 | 71.43% |
| 4/9 | 69.23% |
| 8/15 | 65.22% |
| 4/7 | 63.64% |
| 8/13 | 61.90% |
| 5/6 | 61.54% |
| 4/6 | 60.00% |
| 8/11 | 57.90% |
| 4/5 | 55.56% |
| 5/6 | 54.55% |
| 10/11 | 52.38% |
| 20/21 | 51.22% |
Odds Against Prices And Percentages
| Fractional Prices - Odds Against | Percentages |
|---|---|
| 1/1 | 50% |
| 6/5 | 45.45% |
| 7/5 | 41.67% |
| 8/3 | 38.46% |
| 9/5 | 35.71% |
| 2/1 | 33.33% |
| 5/2 | 28.57% |
| 3/1 | 25.00% |
| 10/3 | 23.08% |
| 7/2 | 22.22% |
| 4/1 | 20.00% |
| 9/2 | 18.18% |
| 5/1 | 16.67% |
| 11/2 | 15.38% |
| 6/1 | 14.29% |
| 7/1 | 12.50% |
| 15/2 | 11.76% |
| 8/1 | 11.11% |
| 17/2 | 10.53% |
| 9/1 | 10.00% |
| 10/1 | 9.09% |
| 11/1 | 8.33% |
| 12/1 | 7.69% |
| 14/1 | 6.67% |
| 16/1 | 5.58% |
| 18/1 | 5.26% |
| 20/1 | 4.76% |
| 25/1 | 3.85% |
| 28/1 | 3.45% |
| 33/1 | 2.94% |
| 40/1 | 2.44% |
| 45/1 | 2.17% |
| 50/1 | 1.96% |
| 66/1 | 1.49% |
| 80/1 | 1.23% |
| 100/1 | 0.99% |
Compare and Contrast Bookmakers
The above are the mechanics of bookmaking, but I am more interested in the nuances and differences between bookmakers during the daily meetings.
So, on an average day, when there are three race meetings, you can see or work out yourself which race has the smallest and biggest percentage.
You can also check the meeting with the smallest and biggest percentage.
You can very quickly see which meetings/races the bookmakers are comfortable with and which where they could be more confident
Understanding Bookmakers
I target just one meeting and investigate that meeting, where it looks like the bookies are scrambling around and unsure of their prices.
This is where the real game begins, where mistakes can be made, and we, as astute bettors, can take advantage.
For example, Betway and Ladbrokes differ significantly in their % on the 1st race but are the same or very similar on all the other races.
Similarly, you might find that one bookmaker consistently undervalues a certain horse, while another overvalues it.
You quickly start to see trends and learn which bookmakers are more risk-averse with their horse racing prices
The Power of Odds Comparison: Ultimate Betting Odds Strategy Guide
Which bookmakers set the movements, which bookmakers are followers, which bookies react with more significant cuts and which bookies are prepared to hold prices?
Odds compilers are creatures of habit like all of us, and despite computer programmes doing plenty of the grunt work, you start to see a house style more, especially on the opening prices.
Odds Grid
Best Betting Sites
Once you have looked at plenty of betting shows, you start to see patterns and which selection the bookmakers think may run well.
The Racing Post currently features nine bookmakers, and checking today's races shows the biggest percentage at 129% and the smallest at 108%.
The biggest percentage difference in one individual race is 13%.(The RP has disappointingly removed this percentage feature—a real shame.)
Odds Compiling
By checking the opening shows of bookmakers and noting that % you can also get a feel for what the bookies think when a horse is withdrawn, especially when that horse is a fav.
If a race, for example, had an opening show of 107%, then the favourite was withdrawn, and the percentage leapt to 120% before the off, you should be able to view which horse the bookie favour.
With the advent of exchanges, percentages have lost some of their sexiness, but they give a snapshot of what the bookies think about a race, and in our constant struggle to beat the bookies, they are a much-needed help.
