Wizard Daily Report and Research - Tuesday, 19 December 2023.

Betting Markets (part 1)

The Field Percentage

A frequently discussed question among punters is:

When should one place the bet?

Bet Early? Bet late?

(Note: For this article the discussion will be confined the last 30 minutes of betting on a race.)

Any casual observer of betting fluctuations would be aware, horses ease, firm, and/or remain steady during the course of betting. 

The odds offered about any horse is equal to its perceived chance of winning the race. So, a $4.00 (3/1) runner is considered to have a 25% chance of success. A $2.00 (1/1) chance has a 0.5 probability, or a 50% chance of success. A $21.00 (20/1) runner has a percentage chance of success of 4.8%, and so on. When we total the percentage chance of all the runners we get the bookmakers field percentage. The margin over 100% is the theoretical profit margin built into the book for that race.

To get an insight into the percentages to which todays corporate bookmakers are betting, I calculated the average percentage to which five of the largest corporate bookmakers were operating on the 16 meetings run last Saturday.

The bookmakers field percentages are presented in three tables:

Table 1: The field percentage of race 4 at each meeting.

Table 2: The field percentage in the race with the lowest number of runners.

Table 3: The field percentage in the race with the highest number of runners.

Table 1 Bookmakers field percentage in race 4 at each meeting.

Except for the outlier at Colac, the final (starting price) field percentage for every one of these races was lower than the percentage at the 30 minute mark. That means, overall, the odds available have been lengthened during the course of betting.

Table 2: The field percentage in the race with the lowest number of runners.

As first seen in the random race (race 4) table, this table which shows the bookmakers field percentage in the race with the smallest number of runners, also has the final percentage lower than the 30 minute percentage.

(Note: Where there were two or more races with an equal number of smallest or largest field size the race chosen for illustrative purposes was the latest at the meeting.)

Table 3: The field percentage in the race with the highest number of runners.

Again, this table which shows the bookmakers field percentage in the race with the highest number of runners, also has the final percentage lower than the 30 minute percentage.

Summary:

Table 1

Between 30m and 15m             7 lower percentage, 4 higher, 5 equal

Between 30m and 5m             13 lower percentage, 3 equal

Between 30m and SP              15 lower percentage, 1 higher

Table 2

Between 30m and 15m             8 lower percentage, 4 higher, 4 equal

Between 30m and 5m             15 lower percentage, 1 equal

Between 30m and SP              16 lower percentage

Table 3

Between 30m and 15m           11 lower percentage, 1 higher, 4 equal

Between 30m and 5m             16 lower percentage

Between 30m and SP              16 lower percentage

A few takeaways from this macro view of the bookmakers betting market.

• The odds, overall, will lengthen during the final 30 minutes of betting.
• The average easing of the market is around 5%, but individual races can vary considerably.
• Not much difference between the randomly selected races (race 4 at each meeting) and the smallest fields.
• Larger fields will tend to bet to a higher percentage, certainly at the outset of betting

In the next article we will start to look into the fluctuations of individual runners.

(to be continued)

Warren - Wiz-Ed

If you have any comment or suggestions about the Wizard Daily articles please feel free to drop me a line at:

Wiz-Ed@everyrace.com