Non Runners

[Fixador]

Would someone be kind and explain to this numpty about non runners please !

I have done a search here of 'reduction factors' - and am still no wiser - and probably more confused

I think I understand with bookies - and rule 4 - that to maintain the overall overround of their book - then in the event of a non runner - the %book of each of the remaining runners is increased - so, the odds of each runner are reduced. ( all other factors being unchanged ! )

But 'reduction factors' on betfair - i read BF's 'help' - and am left feeling helpless

How does a non-runner affect my bet?

For our horseracing markets we guard against possible non-runners with a system of Reduction Factors (similar to Rule 4 with traditional bookmakers). Each horse is allocated a Reduction Factor, based on its likely chance of winning the race. Should a horse be declared a non-runner, the Reduction Factor will be applied to the prices of all matched bets, for both backers and layers.

This is to ensure that layers are not unfairly treated and exposed to large liabilities when the chances of other horses winning have improved. The Reduction Factors are designed to be fair to both backers and layers.

Now edging closer for the prize numpty question ! - if a selection has got (NR) at the end of its name - ok - its a non runner. It seems from the above - the reduction factor associated with this now NR is applied to all of the other runners - so if the reduction factor of the NR was 10 - then the odds of a runner that was say 21 now reduces to:-

= 1+( (OLDodds-1)*(100- reductionfactor)/100)

which would be = 19

Before I delve deeper into my personal mire of ignorance ... is the above correct ?

What i suspect i am leading upto is to ask about - is there a discrepancy occurring - since Rule 4 sends the bookies odds higher, but BF reduction factor sends the BF odds lower ?

[Ian]

Put simply, the bookies R4 is applied to the winnings only whereas on Betfair it is applied to the winnings AND the stake.

So if a horse is 20/1 with the bookmakers and there is a 10p R4, the revised odds become 18/1 (19.0).

If a horse is 21.0 on Betfair and there is a RF of 10%, the revised odds become 18.9 (17.9/1).

The bookmaker's method of R4 does not maintain the over round whereas Betfair's way does.

[Fixador]

Thanks for sorting me out Ian

Ok, have i understood this correctly :-

The displayed odds are NOT adjusted - both bookie ( after declaration of R4 ) and BF ( after NR declared ) - they remain the same - BUT, the bookie payout on winnings is reduced, and BF returns a percentage of my (already matched ) stake ( whether Lay or Back ) PRIOR to the OFF ?

Please bare with me, as i have noticed something screwy occurring in BF when there are NR's - i am trying understand the situation, so i can eliminate the screwiness - sorry i cant explain it any better than 'screwiness' as i am still trying to understand

[orange]

Betfair will suspend the market and change the odds to the new prices in line with the reduction and matched bets will be moved in line with this and stakes will be reduced also, all unmatched bets will be cancelled and the market starts again.

[Fixador]

Hi Orange,

Oh Strewth - so the 21.0 odds subject to a 10% RF - actually do change to 18.9 in the market.

Wow - thanks - that helps towards the 'screwiness' i have been seeing

What about bookies and rule 4 - do they also rehash all of their odds as soon as a NR is declared ?

[orange]

Sometimes they leave the market as it is if there is not enough time to reform the market or they can put a rule 4 on all winning bets placed before a certain time.

[Fixador]

Cheers Orange,

being digging around BF rule & regs

(1) Win mkt : if a NR RF = 25 %, then if another runner had odds of 8.0 - this would be reduced to 6.0 ie : NewOdds = OldOddsx(100 -%RF)/100

(2) In PLACE mkt - its different - it would be a reduction on potential winnings ie from 8.0 to 6.25 ie : NewOdds =1+(OldOdds-1)x(100 -%RF)/100

(3) Win mkt : if RF <= 2.5% then the RF isnt applied, but it is in the Place mkt !

Clear as mud then with Bookies ! ha ha ! I wonder - do they ever invoke rule 4 for bets not yet taken ? - Oh you have already answered that.

Any idea - do Bookies reform the market ( or not ) based on something like being a NR declared prior to a set time prior to the scheduled OFF - and not reform if the NR is declared after set time ?

many thanks

[orange]

It's basically up to them, they can work it either way as they only have to pay on the winner and they can set the rule 4 on the winners price and adjust it accordingly,

Betfair have to adjust the price as it affects all trades done on all runners and obviously on both sides of the market.