71. weight effect on sand

7/30/2019 71. Weight Effect on Sand

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WEIGHT EFFECT ON SAND

This month we are going to examine the effect the weight a horse isallocated has on results on the All Weather.

If we study results from Lingfield, Southwell and Wolverhampton from theseasons 2001 to 2004 (inclusive), we can see from the following table that as theweight band increases, so does the strike rate.

WEIGHT WINS RUNS STRIKE% LSP LSP%

7.8 8.0 110 2539 4.33 -1056.84 -41.62

8.1 8.7 493 7412 6.65 -3070.20 -41.42

8.8 9.0 1807 20549 8.79 -6734.60 -32.77

9.1 9.7 1432 14944 9.58 -4154.98 -27.80

9.8 10.0 900 8327 10.81 -1744.81 -20.95

This doesnt really tell us much because more horses towards the head ofthe betting find themselves in general allotted more weight than those near thefoot of the weights. We need to narrow our search down to a level playing fieldbefore we can start making any firm opinions. Well do this by concentratingsolely on SP favourites.

Now if we examine the weight band stats, we see that there seems to belittle advantage in any area


7.8 8.0 16 53 30.19 -7.67 -14.47

8.1 8.7 111 393 28.24 -82.98 -21.11

8.8 9.0 601 1839 32.68 -126.63 -6.89

9.1 9.7 453 1662 27.26 -150.24 -9.04

9.8 10.0 341 1198 28.46 -55.46 -4.63

Now the table shows a much more balanced view. Clearly the unevendistribution of the horses with the better chance of victory (i.e. those towards the

front of the betting) was skewing the figures in reality the strike rate is more orless level across the board.

The next step in trying to create a true reflection of the effect of weight isto narrow the research down to handicaps only. In these races the runners areallotted weight in accordance to their official ability with the better horses


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carrying more weight than their lesser rivals which means that they are morecompetitive than non-handicaps and therefore a more reliable guide to statistics.


7.8 8.0 10 36 27.78-2.14 -5.94

8.1 8.7 29 154 18.83 -57.02 -37.03

8.8 9.0 125 507 24.65 -69.44 -13.70

9.1 9.7 240 931 25.78 -55.74 -9.76

9.8 10.0 212 853 24.85 -70.90 -13.38

Nothing conclusive there as apart from a dip in the 8.1 8.7 range (probablydue to the small sample size) the figures are more or less even across the board.That changes, however, when we break the results down by track

LINGFIELD


7.8 8.0 2 6 33.33 1.25 9.58

8.1 8.7 3 41 7.32 -29.30 -72.69

8.8 9.0 37 159 23.27 -26.53 -13.06

9.1 9.7 84 307 27.36 5.69 1.80

9.8 10.0 83 289 28.72 30.68 12.29

SOUTHWELL


7.8 8.0 1 14 7.14 -10.50 -75.00

8.1 8.7 17 54 31.48 2.13 3.94

8.8 9.0 50 168 29.76 7.70 4.58

9.1 9.7 72 271 26.57 -13.70 -5.06

9.8 10.0 60 251 23.90-44.92 -17.90

WOLVES


7.8 8.0 7 16 43.75 7.11 44.44


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8.1 8.7 9 59 15.25 -29.85 -50.59

8.8 9.0 38 180 21.11 -50.61 -28.12

9.1 9.7 84 353 23.80 -47.73 -13.52

9.8 10.0 69 313 22.04 -56.66 -18.10

The small sample size of the lower weight bands are creating a false impressionof fluctuating strike rates, so to alleviate this well group together all runnerscarrying 9-0 or less

LINGFIELD


7.8 9.0 42 206 20.39-54.58 -26.50

9.1 9.7 84 307 27.36 5.69 1.80

9.8 10.0 83 289 28.72 30.68 12.29

SOUTHWELL


7.8 9.0 68 236 28.81 -0.67 -0.03

9.1 9.7 72 271 26.57 -13.70 -5.069.8 10.0 60 251 23.90 -44.92 -17.90

WOLVES


7.8 9.0 54 255 21.18 -73.35 -28.76

9.1 9.7 84 353 23.80 -47.73 -13.52

9.8 10.0 69 313 22.04 -56.66 -18.10

This gives a more realistic picture, and throws up an interesting set ofresults. While Southwell and Wolves have little difference in their weight bands(Southwell seemingly slightly favours those in the lower half of the weights), itsthe results from Lingfield that catch the eye.


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There is a considerable jump of almost 7% in the strike rate of 20.39% forthose runners carrying 9-0 or less to 27.36% for those carrying between 9-1 and9-7. The strike rate increases even further to 28.72% for the 9-8 to 10-0 band.

This doesnt surprise me in the slightest, as the Polytrack surface that is in

place at Lingfield has a lesser effect on energy distribution than on the Fibresandsurfaces at the other two courses (towards the end of 2004 Wolves replaced theirold Fibresand with Polytrack, so all but a couple of months worth of statistics inthis analysis came on the old surface).

The Polytrack surface has a lesser pull on energy output due to theelasticated surface allowing the horses to bounce off the ground, and its logicalto assume that this is the reason for the abnormality in the results in the previoustable for Lingfield. The less energy-demanding a race is, the less effect weightwill have on a horse, so therefore those allocated larger weights in order to slowthem down enough to create a level playing field (as it the sole purpose of

handicaps) will have their disadvantage lessened.

So we can see that SP favourites at Lingfield running in handicapscarrying 9-1 or more actually make a profit from backing them blindly, with isexcellent considering there have been almost 600 bets during the last 4 seasons.

Concentrating on just these qualifiers that carry 9-1 or more, we can seefrom further analysis that the effect of the draw is quite strong

DRAW QUINTILE WINS RUNS STRIKE% LSP LSP%

Lowest quintile 37 115 32.17 27.13 23.59

Lowside quintile 38 125 30.40 19.51 15.61Middle quintile 39 133 29.32 17.79 13.38

Highside quintile 29 121 23.97 -18.57 -15.35

Highest quintile 24 102 23.53 -9.49 -9.30

Clearly there has been a major disadvantage in being drawn in the highest40% of the field, with a clear drop in the strike rate and a level stakes loss. Goodprofits have been made from the lowest 60% of the draw, so these are thequalifiers we will continue to analyse.

The final part of the jigsaw is to look at the different results produced bymale and female horses

SEX WINS RUNS STRIKE% LSP LSP%

filly/mare 20 76 26.32 -7.67 -10.09

colt/gelding 94 297 31.65 72.10 24.28


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As you can see, there is a ROI loss of over 10% on the females, yet instark contrast an impressive ROI profit of almost 25% on the males.

As Wolverhampton has now changed its surface to Polytrack, there is noreason why this system should not work at that venue as well, as indeed in the

future at the various new AW courses being built.

RULES

1. Polytrack only2. SP favourite only3. Horse must be allotted (ignore jockey claim) 9-1 or higher (ignore amateur

races where all weights are raised)4. Lowest 60% of the draw only to be considered (this is only applicable to

Lingfield, not enough data at present for Wolves)5. Male horses only

Polytrack was introduced to Lingfield in November 2001 and toWolverhampton in 2004. It seems perfectly logical to me to assume that the poorrecent Topspeed results from these two tracks is down to this new speed-ratingunfriendly surface. Southwell, after all, has continued to produce consistentfigures in recent years, as has turf.

So from now in this study, we will consider only those races which tookpart on non-Polytrack all-weather surfaces (Equitrack & Fibresand).

Experience has taught me that race distance is very much a key factor in

the study and use of speed ratings; the longer the race, the less likely that a truepace will ensue, leading to slow times and unreliable form. With this in mind, wellnow look at the stats from the last 5 seasons of these Topspeed selections onnon-Polytrack all-weather surfaces (SP


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YEAR WINS RUNS STRIKE% LSP LSP%

2000 159 416 38.22 18.52 4.45

2001 112 309 36.25 22.73 7.36

2002 59 168 35.12 10.51 6.26

2003 74 174 42.53 40.57 23.32

2004 62 200 31.00 -27.29 -13.65

TOTAL 466 1267 36.78 65.04 5.13

The main thing to notice here is the poor return from 2004, but the vastmajority of these losses came from Wolverhampton in the months leading up tothe laying of the new Polytrack surface. The Fibresand at Wolverhampton was inno fit state for horse racing in the latter stages of its existence and Im sure this isthe reason for the poor results.

The final filter we are going to add here is field size, and once again it is alogical inclusion small fields are far more likely to produce a false pace (andtherefore a false and unreliable result) than larger ones, and the following field-size breakdown supports that theory.

FIELD SIZE WINS RUNS STRIKE% LSP LSP%

2-4 runners 9 21 42.86 -2.86 -13.62

5-7 runners 83 231 35.93 -19.26 -8.34

8-10 runners 181 472 38.35 34.25 7.26

11-16 runners 193 543 35.54 52.91 9.74

TOTAL 466 1267 36.78 65.04 5.13

At least eight runners in a race is a must have rule for this method, asspeed ratings are worth less as the field size diminishes.

As Lingfield and Wolverhampton have made the transition to Polytrack,Southwell is the only current all-weather course to have a non-Polytrack surfacein place, so it is this track which will provide the selections for this method.

So the final rules and results are as follows

a) Southwell all-weather races onlyb) Horse must be top rated by Topspeedc) Horse must be sent off at shorter odds than 4/1d) Only consider races 10f or shorter in distancee) Only consider races with at least eight runners


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YEAR WINS RUNS STRIKE% LSP LSP%

2000 123 324 37.96 27.73 8.56

2001 90 261 34.48 11.39 4.36

2002 51 144 35.42 12.76 8.862003 67 148 45.27 49.86 33.69

2004 43 139 30.94 -15.58 -11.21

TOTAL 374 1016 36.81 86.16 8.48

71. weight effect on sand

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