Rule 4 - horses withdrawing the previous day?

[HenryTD]

I have been getting data about rule 4 deductions from the William Hill website. The descriptions of the deductions look like the sample below:

Win - 35p reductions on bets placed between 08:54:41 and  09:48:43
Win - 15p reductions on bets placed between 09:48:44 and  12:32:38
Win - 10p reductions on bets placed between 00:00:01 and  09:04:40
Win - 20p reductions on bets placed between 00:00:01 and  10:01:43
Win - 20p reductions on bets placed between 10:01:44 and  12:15:05
Win - 15p reductions on bets placed between 00:00:01 and  15:16:14
Win - 35p reductions on bets placed between 00:00:01 and  15:03:29
Win - 25p reductions on bets placed between 00:00:01 and  14:35:28
Win - 25p reductions on bets placed between 00:00:01 and  14:23:57
Win - 30p reductions on bets placed between 00:00:01 and  14:02:44
 

I have collected a large number of these and was expecting to see some instances where William Hill indicated that the withdrawal happened the day before the race but all the times listed come without a date. So either by chance no horse has ever withdrawn the day before a race or perhaps William Hill don't supply enough information to tell.

One thing that would help clarify things is if anyone can think of any example races in which one or more horses withdrew the day before the race.

 

[BillyHills]

I think its basically a WH site problem whereby they cant state a time before midnight.

Anything that says 00:00:01 has been withdrawn the day before.

Think about it, no trainer withdraws a horse at 1 second past midnight and if they did Weatherby's wouldnt answer the phone or read the email,  lol

 

 

[BillyHills]

Ok

Heres an example

Regular on Tues August 4th was withdrawn at 8.18pm the night before

Hills state the deduction was from 0:00:01

 

 

@HenryTD

[HenryTD]

Thanks BillyHills for the detailed reply... of course my next question is: how do you know that Regular withdrew at 8.18? Maybe I could collect some data from that source.

 

[HenryTD]

I have now worked out that your data probably came from flatstats... but that leaves me with two problems:

1. I am not sure if the flatstats non-runner info is available for races more than 7 days ago.

2. The flatstats info is still ambiguous. It Simply displays a time and not a date for the withdrawal. It just so happens that in this particular case you can deduce that the withdrawal must have been the previous day but this will not always be the case, especially for late evening races.

Does anyone know of any unambiguous withdrawal time data source?:

 

Edited August 6, 2018 by HenryTD

[BillyHills]

Try the BHA website, they are the governing body that supposed to have these details.

You are going to a lot of trouble to find out when a horse was withdrawn?

 

[BillyHills]

Just thought of a couple of things worth noting:

Flatstats figures are complied from Betfair reduction factors, so maybe the Betfair results data could be a way forward. I know they used to do an archive results file for betfair SP's??

Also the R4 deductions on the Hills site is only applicable to 'their' prices so the R4's could be different on the Paddy Power prices for example, so not a true 100% accurate guide although perhaps near enough?

Over an out

 

[Valiant Thor]

Im just wondering (being the inquisitive type that I am)

What statistical knowledge (if any) is to be gleaned from knowing the pre/post race price of a horse after being withdrawn, unless your the reincarnation of Nostradamus or Baba Vanga and can predict when future horses are due to be withdrawn, then it seems to me like a fruitless en devour ,( then again it could be the next  best thing since electric cars  )

Edited August 6, 2018 by Valiant Thor

[HenryTD]

The BHA website lists non runners but does not say when they withdrew.

The reason I am going to so much trouble is as follows: I subscribe to the proform database which gives "evening", "breakfast" and "morning" odds which are the odds at Bet365 at pre-defined times. I am doing some back-testing of assorted prediction algorithms and betting strategies. So for example say I wanted to know what would my winnings be if I always bet the day before the race and got the evening odds (8.30pm). It is then essential to know about any rule-4 deductions that may be made to my winnings. I can find the approximate size of the deductions (using william hill data) but what I can not find anywhere is the time of withdrawal so I can not find out if the deductions apply at all. What I'm doing right now is simply looking at races with no non-runners but that means throwing away half my potential data set :-(

[Valiant Thor]

Thanks for the informed answer

All my betting is pure data related

But I just cant see any correlation whatsoever with withdrawn horses and race outcomes, it is nothing that can be predicted pre race (unless the race is fixed),If your doing it post race then its totally irrelevant due to the confines of previous statement.

Even after a horse is withdrawn a total change in the market occurs, horses are backed that wouldn't normally be backed ,false favs & numerous other anomalies , best of luck but you seem to be looking for a black cat in a coal cellar IMO

[HenryTD]

Hi Thor. I am puzzled as to why you are puzzled!

Say that a race occurred on June 12th 2017. Say that the race card listed both Dobbin and Lucky Star amongst others.

I also have the information that Lucky Star was withdrawn from the race at some (unknown) point.

I have in my database the fact that at 8.30 pm on 11th June Bet365 were offering odds of 10/1 for Dobbin - but I have no idea whether Lucky star had already withdrawn or was yet to withdraw when these odds were offered.

I also have the information that Dobbin won the race.

I then want to test out the profitability of a particular algorithm by looking at past data, perhaps 1000 old races including the one on June 12th. Say that my algorithm chose Dobbin as the favourite in the race. So I need to know how much would I have won if I had bet on Dobbin at 8.30pm.

The answer to my question depends on exactly what date/time Lucky star withdrew and what the rule 4 deductions would have been.

 

Edited August 6, 2018 by HenryTD

[Valiant Thor]

I back a few horses that are NR's they make absolutely no difference to my P/L as I get my money back.

If I have a horse in the race with a NR I pay the R4 if my horse wins thats life, knowing whether a horse is a NR or not makes no difference, my profit is my profit and knowing whether a horse is a NR or not is totally irrelevant as there is nothing I or you can do about it, you are looking at a problem that you have no control of whatsoever.

So when you test your 'algorithm' in the real world will you take into account how much to put on just in case a horse gets withdrawn and if not why not as that is what your trying to work out.

Edited August 6, 2018 by Valiant Thor

[HenryTD]

If I ignored rule 4 deductions altogether then my back testing would end up overestimating my profits. If I always took off the full rule 4 deductions then my back testing would underestimate my profits. Amongst other things I want to determine the likely profitability of my system - how can I know this without handling rule 4 properly?

 

[Valiant Thor]

I give up ......................................SIGH

You base profitability on FACT not "would have ,could have , should have ,if's or buts "

"Would" have won £x if horse y wasn't withdrawn , but it was and you didn't FACT

"Could"have won £x if horse y wasn't withdrawn , but it was and you didn't FACT

"Should" have won £x if horse y wasn't withdrawn , but it was and you didn't FACT

"If" horse y wasn't withdrawn I would have won £x, but it was and you didn't FACT

"but" for horse y being withdrawn I could have won £x ,but it was and you didn't FACT

I "could" have won £62 mill last week on the lottery but 7-26-36-38-43 stars 6-12 were not the numbers I picked , but I'll add the £62 mill to my profit and loss anyway because I "could" have won it , even though I didn't .............get my drift

I understand what your trying to do

If your system says back A @ x price would you still have that selection price if horse y was already withdrawn...yada yada yada

You must be the most unluckiest punter on earth that you have that many R4's your P/L all boils down to the need to estimate the effect of  R4's on it.(or your just over complicating things)

Take out the R4 races and just do a A v E to get a snapshot of how things might pan out all being equal, R4's are just an unfortunate outlier that has to be tolerated.

Ps

 MY R4's

2 this year

3 in 2017 and a dead heat

3 in 2016

so I aint going to lose any sleep over it 

Edited August 7, 2018 by Valiant Thor

[HenryTD]

Averaged over the whole year, about half of all races have one or more non-runners. The only way you have had so few r4 deductions is if you always bet at the last minute. But there are good reasons to believe that there may be better value available in the morning or the day before.

[BillyHills]

Actually you are better off 90% of the time taking the R4 deduction over betting late and taking a price close to the SP.
So just accept that sometimes you will get a deduction but safe in the knowledge that you beat the price anyway and if your 'system' throws up enough winners you will be ok anyway.

As Valiant says, its just part of racing, since we went to 48hr decs the amount of NR's is silly.

I'm not sure what your figures show but the earlier you take a price the better off you are in my experience.
Once a NR is declared it gives the bookies chance to reform the market and balance the books and horses are cut without a penny being layed.

 

[Valiant Thor]

3 hours ago, HenryTD said:

Averaged over the whole year, about half of all races have one or more non-runners. The only way you have had so few r4 deductions is if you always bet at the last minute. But there are good reasons to believe that there may be better value available in the morning or the day before.

most of my bets are not just before the off, I get what i can on the night before online from the books that still take a bet from me which isnt a lot believe me , the rest I have to put on around 10 am at the bookies shops,  you must be betting in all the rag arse handicaps which I wouldn't touch with free money

Edited August 7, 2018 by Valiant Thor

[MCLARKE]

I can see where Henry TD is coming from in trying to verify the profitability of a system based on early prices. I think to find all the relevant data would be a big task.

Personally when I am testing a system I like to make a profit at SP in the knowledge that in reality I could improve that by 10% by using early prices or BSP.

To judge a system on profitability based on BOG may turn out to be a waste of time because if you do hit on a good system it will not be long before the bookies will not allow you to bet at BOG anyway.

[HenryTD]

Take a look at the proofing of the very impressive Lucky 7 Naps on Betfan.com:

https://members.betfanplus.com/proof/?oppid=34&p=2&odds=1&stake=1&timeframe=4&month=2018-08-07

You will see that the system makes a nice steady profit with BOG but loses money with SP or BetfairSP. Anyone trying to beat the bookies based purely on testing against SP may get unduly discouraged. Early bets/BOG are undoubtedly a good strategy and early prices are now part of the proform data (beginning mid 2016) but then you need to know about rule 4 deductions which sadly are not included in proform. You can of course only consider races that turned out to have no non-runners.

I noticed that at 8.30pm this evening (7th Aug 18) that there wasn't a single withdrawal in any race tomorrow. Maybe withdrawals the day before the race are super rare? If it turns out they are, then maybe simply assuming that all rule4 deductions are applicable for "evening prices" might be a reasonable approximation.

With regard being blocked by bookies - well if you have a good system you could always become a tipster!

[BillyHills]

Quote

I noticed that at 8.30pm this evening (7th Aug 18) that there wasn't a single withdrawal in any race tomorrow. Maybe withdrawals the day before the race are super rare? If it turns out they are, then maybe simply assuming that all rule4 deductions are applicable for "evening prices" might be a reasonable approximation

Earthly in the first race at Ponty was withdrawn last night. (7.50)

Also Zabaletaswansong in the 540 at Kempton. (midnight)

Screenshot from Betfair showing when they were withdrawn and reduction factors applied:

 

[HenryTD]

Thanks BillyHills, seems I missed Earthly - that's very useful that you spotted that - so perhaps it's not so rare after all.

 

[BillyHills]

I do the PL Tips from 4.30 - 6pm and look at every betting market for Bet365, Paddy Power, Corals and Betfred.

I would say up until 6pm i see around 2/3 at most NR's, not sure about later on as I don't revisit the markets until much later the next morning.

[HenryTD]

That's very useful to know. Thank you.

[HenryTD]

I just went to see how William Hill would report there races with the non runners (who's time of withdrawal we now know). Take a look at the screenshot of the 5.40 at Kempton on the 8th Aug.

It labels both Zabaletaswansong and American Patrol as non runners but only lists the rule 4 deduction for one of them!...

Thinking out loud here...

If William Hill simply did not take bets the day before the race, then only reporting rule 4 deductions for horses that withdrew on the day of the race would make perfect sense. So perhaps WH don't take bets the day before - or they sloppily put data on their site *as if* punters could not bet on the day before... just a theory.

EDIT: Oops. Just checked the 2.20 at Pontefract. WH reports both the non runners without mentioning any rule 4 deductions at all... this is crazy.

 

Edited August 9, 2018 by HenryTD

[BillyHills]

In the 220 Earthling was withdrawn before Hills had formed a market I think so there is No R4 for their customers.

when i do the odds i can never use Hills as there are never any prices until later in the evening and I need them before 6pm. I'm guessing any very early NR's escape R4's at Hills hence the confusion.

 

[BillyHills]

P.S. There is a NR for Friday already

Caribbean Spring 5.20 Wolverhampton

Be interesting to see what time they give for the withdrawal.