The Penetrometer Explained

In the hi-tech world we live in, punters expect every skerrick of information to be placed before them, in their quest to spot an elusive winner.

The penetrometer – a device used to accurately assess a track rating- has had both its admirers and its critics over time.

Long before penetrometers came on the scene, I personally felt many track ratings that were given out, were incorrect. One or more of the race club committees, stewards and course curators would often engender enthusiasm in punters hearts by declaring a track surface “dead”, when in fact it was later that same day proven to be “slow”, as evidenced by times run in races. The simple and probable actual happening would be that a downgrade in a track rating may well lead to a downturn in betting turnover!

Accurately measured, the penetrometer gives the punting public an exact reading when it is taken on race morning.

Doomben Racecourse Manager Warren Williams has been using the penetrometer at Doomben for some time. Doomben and the Gold Coast clubs each take a penetrometer reading on race mornings. Brisbane’s other metropolitan track at Eagle Farm doesn’t use a penetrometer.

Records taken over time, in my opinion, will show penetrometers give an accurate assessment of the track rating. On rain affected tracks of “slow” and “heavy”, I have found that horses will perform to a consistent level on the same track given similar penetrometer readings.

Penetrometer readings are unique only to the track they are taken on, due to different soil compositions of individual tracks. For instance, in the most recent Saturday meeting when both venues of Doomben and the Gold Coast raced on the same day (30/5/2005) – a “dead” track was posted by stewards at both tracks. The Doomben penetrometer reading was 5.03 (with the rail out 4 metres the entire course), whilst at the Gold Coast, even though their track was “dead” also, their penetrometer reading was way below Doomben’s at 4.23. The Gold Coast rail on the day was out varying distances up to 8 metres.

Down south, on the exact same day (30/5/2005), Rosehill raced on a “good” track with the rail out 6 metres and their penetrometer was 4.15. Sandown (Hillside) was Melbourne’s venue that day and they had a “good” track with the rail in the true position and yet their reading was well above Sydney’s at 4.81.

So let’s summarize those penetrometer readings from 30/5/05 in a graph to help us conclusively understand that penetrometer readings are like fingerprints and are therefore unique to each individual track.

Track                Penetrometer            Rail position        Rating

Doomben              5.03                      4 metres                Dead

Gold Coast           4.23                       8 metres               Dead

Rosehill               4.15                         6 metres               Good

Sandown (H)       4.81                         True                      Good

It is a good idea from a punting perspective to keep a book and list the penetrometer readings and rail placements for each track you bet on and also at the end of each day to write the winners names down. It becomes even more relevant for future “slow” and “heavy” ratings.

When tracks don’t use penetrometers the answer is a pineapple. For instance when I saw the dust coming up in Eagle Farm Race 1 Saturday, I thought that track would be “fast” not “good”. Sure enough Virage De Fortune runs blistering time leading all the way in the Sires Produce. Later on, Sir Breakfast ran near track record time when recording 1.8.7. Sir Breakfast had won at the same track and distance on a “good” track almost two years to the day (11/5/03) and ran 1.9.2 with 60.5 kilos. On Saturday, he ran half a second quicker than he’s ever run there. If the track was “fast” then in the last race the dry tracker Natural Blitz should have appreciated it. He bolted in and made them look second rate. His trainer Doug Harrison has always said of tracks for his horse “the harder the better”. It took till start 45 to prove the man right in my opinion. However history will say Natural Blitz won on a “good” track. A simple penetrometer reading may have tipped the scales in the other direction. (ie. “fast” instead of “good”) in the morning. Once again the word “fast” is a dirty word when discussing tracks ratings– as trainers don’t want their horses jarring up. Natural Blitz has officially never started on a “fast” track.

The other thing to understand is that the penetrometer readings are generally done in the 6am to 7am timeframe on race morning. If a fine day with a top of 35 degrees is forecast, naturally the track will dry out further between 6am and the first race at say 12.30pm. So a 4.35 penetrometer 6am race day reading at Doomben would become probably about 4.15 if a penetrometer reading was taken before the first race and the weather had stayed fine and was heading towards 35 degrees. Conversely if showers happen during the morning or afternoon the penetrometer reading will go in the opposite direction – the margin of change being commensurate with the amount of rain. Track drying out is influenced by the season as well. Understandably a summer track will dry out far quicker than a winter track.

So what does a penetrometer look like and how does the Racecourse Manager arrive at his reading on race day.

Doomben’s Racing Manager Warren Williams kindly explains to readers about penetrometers and I take this opportunity to publicly thank him for his input into this article and also for his availability to let the website readers know the latest weather and track report from his track on Friday evenings, during the Doomben part of the Winter Carnival.

Warren’s article reads:-



Penetrometers have been used for many years to assist Racecourse Managers and Stewards with track ratings. This device comes from the road building industry where they used a device to measure the road profile prior to the final surfacing of asphalt. This device was then modified to measure soil hardness in turf.


Penetrometers are used in the thoroughbred industry by many metropolitan tracks and also some major provincial clubs. The penetrometer is constructed out of a metal (stainless steel) and is currently manufactured in Melbourne. The penetrometer description is as follows:
A 1 kilogram weight is released by a trigger action and falls 1 metre down a shaft, which in-turn hits a 1 centimetre square rod into the soil profile. The 1 centimetre square rod has 1 centimetre increments as the measurement for the depth the rod that has entered into the soil profile. This action is undertaken 3 times in the one position, therefore giving 3 readings eg: 2.5, 4.5, 6.5.


A formula is used to calculate the reading and is based on the average figure for the entire course. To obtain this figure there are 6 readings taken every 200m around course. Three of the 6 readings are taken 2m from the running rail and then the remaining 3 readings are taken 4m from the running rail. Each reading is recorded and then all figures are entered into a formula that will provide an average. This average then becomes your race day penetrometer reading and will correspond to your set ratings – Fast / Good / Dead / Slow / Heavy. Eg: Track – “Good”, Penetrometer – 4.25