How merit ratings set the weights in SA handicaps, and how to read them

What a merit rating actually measures

South Africa adopted merit handicapping in 1999, according to the National Horseracing Authority's 2019 Guide to Handicapping. The aim was a system the rest of the racing world could read. The guide defines a merit rating as "an assessment of the ability shown on the track which is expressed in half-kilos". The rating is a weight, and that is the key to reading it.

The NHA rule quoted in the handicapping guidelines defines a handicap as a race in which the handicapper allocates the weights "for the purpose of equalizing their chances of winning" (NHA Rule 47.4.2). Under merit handicapping, a horse's weight comes from what it has shown on the track. The guidelines say there is "no arbitrary or standard penalty" for winning.

A horse gets its first official rating once it has won a race or raced three times. Ratings are reconsidered every time it runs.

From rating to kilograms: the MR80 example

The NHA guide works through a hypothetical MR80 handicap with five runners. The top-rated horse carries the benchmark top weight, here 60 kg. Each horse then carries half a kilogram less for every point it is rated below the top horse:

Check any line yourself: horse 5 is 10 points below the top, and 10 × 0.5 kg = 5 kg, so it carries 60 − 5 = 55 kg. When you see "MR80" in a race name, the number tells you the rating level the weights are built around.

Plates are different

Not every race is a handicap. In plate races the conditions, not the handicapper, set the weights. The 2019 guide lists them:

Plates also give 0.5 kg off for each unplaced start, up to 3 kg.

Why weight matters: the drag effect

The guide states the working assumption that "one kilogram slows a horse down by one length over one mile (1600m)". Weight drags more the further a horse runs. Shorter races need more weight to cost a length, and longer races need less. The Citizen's bluffer's guide to merit rating uses the same rule of thumb.

Handicappers turn beaten lengths into rating points with a scale that depends on distance. These rows come from the NHA handicapping guidelines, in half-kilo units (that is, rating points):

So a horse beaten 4 lengths in a sprint ran about 9 points (4.5 kg) below the winner. Over a long trip, the same 4 lengths is worth only 6 points (3 kg). The 2019 guide gives the same idea in pounds per length for domestic races: 2.3 lb from 800m to 1299m, 2 lb from 1300m to 2000m, 1.7 lb from 2001m to 2400m and 1.5 lb beyond 2400m.

How a rating moves after a race

The handicapper does not simply raise the winner. The process runs like this:

1. Pick a line horse. This is a runner of known ability whose run is used as the yardstick for the rest of the field.
2. Convert the margins. Each horse's weight carried, less the weight value of its beaten margin, gives a weight value for its run.
3. Compare with the line horse. Horses that ran better than the line horse rate higher, and those that ran worse rate lower.
4. Apply judgement. Was the start fair? Did the horse race wide, get impeded, or face a false pace? Did the distance and going suit?
5. Adjust. In handicaps the winner is assumed to have "beaten the handicap", so its run is not used as the yardstick for the race.

The Citizen's example is the Michaelmas Handicap at Greyville over 1900m, where the winner, Blackball, went from 103 to 107: a 4-point rise, or 2 kg more next time in a handicap. The NHA guidelines work through a similar case, an FM84 handicap in which the winner, Cocoa Beach, went from 83 to 87.

The guidelines add some caps. The winner of a minor plate race will not move by more than 6 points. A maiden winner aged four or older will not be rated higher than a nett 70, and a three-year-old maiden winner not higher than a nett 78. A horse returning from a layoff can receive an allowance of up to 3 points after 210 days off and 5 points after 365 days or more.

Ratings are not final if a trainer disagrees. According to the Citizen, an appeal goes to an independent tribunal. Weight is carried either "live" (the jockey) or as "dead" lead weights in the saddle.

Gross and nett ratings: weight-for-age

Younger horses are still maturing, so they receive a weight-for-age (WFA) allowance from older horses. The guide's example is a three-year-old called Explorer, with a gross rating of 84, racing over 1200m or less:

In August, 14 half-kilos is a 7 kg allowance, so the nett rating is 84 − 14 = 70. The allowance shrinks every month. If the horse keeps running to its mark, its nett rating climbs towards 84 without any improvement in form. When a three-year-old's nett number rises through the season, check whether it has actually improved or whether the WFA allowance is simply running out.

Reading a racecard and a form line

The NHA's sample rating profile shows the columns you will see on South African form: venue, date, going, race class, distance, draw, finishing position, lengths behind the winner (LBH), the weight-for-age allowance, the pre-race rating, the race merit rating (RMR) and its nett version (NRMR), the starting odds and days since the last run. The profile also shows separate turf and sand ratings. Once a horse has run at least three times on both surfaces, the two are treated independently.

A practical way to use this as a punter:

• Compare the race's rating level with each horse's current MR. A horse rated well below the top weight carries less. A horse at the limit carries the most.
• Look at the RMR, not just the finishing position. A fourth-placed run with an RMR above its rating can be better form than a soft win.
• Check the distance aptitude. The NHA uses the SMILE categories: Sprinter (1000m to 1300m), Miler (1400m to 1800m), Intermediate (1900m to 2100m), Long (2200m to 2700m) and Extended (2800m plus).
• Remember the aim. A perfect handicap ends with the field bunched at the line. That is why handicaps make open betting markets and are rarely easy to call.

Ratings explain the weights, but they do not tell you the price. To weigh up what a horse pays, read fixed odds vs tote and how tote pools work. If betting stops being fun, the responsible gambling page has the tools, and the South African Responsible Gambling Foundation's toll-free line is 0800 006 008, open 24/7.