What the acronyms actually mean
SP stands for Starting Price – the odds the bookmakers lock in the moment the race begins. BSP is the Betfair Starting Price – the market-derived odds at the instant the tote closes, usually a tick later.
Why the difference matters
Look: a traditional bookie sets his odds early, hoping to balance the book. Betfair’s algorithm watches every wager, adjusting the price until the last second. That tiny timing gap can swing a win by a full percentage point.
How the numbers are calculated
Here is the deal: SP is a simple average of the odds offered across the track, plus a margin for the house. BSP, on the other hand, is a weighted average of all matched bets, stripped of any commission. The result? BSP often sits closer to the true market value.
Example in action
Imagine Greyhound “Lightning Bolt” is listed at 5.0 SP. The Betfair market, flooded with savvy punters, settles on a BSP of 4.6. That 0.4 difference means a £100 stake returns £460 instead of £500 – a £40 edge.
When to favour one over the other
And here is why seasoned bettors chase BSP on Betfair platforms, especially when the field is tight and liquidity high. If the track is small, or the race is a long-shot, the SP might actually be kinder, because bookies widen the spread to protect themselves.
Practical tips for the bettor
First, always check the live market before the gate drops. If the BSP is significantly lower than the SP, consider backing on Betfair – you’ll lock in better odds.
Second, watch the turnover. Heavy turnover pushes BSP toward the true probability, while a thin market can inflate it.
Third, be wary of “price drift” – the longer you wait, the more likely the BSP will move away from the SP, sometimes dramatically.
Finally, remember the rule of thumb: if the SP is tighter than the BSP, the bookmaker is probably over-rounding. Flip the bet to the exchange for a cleaner price.
For a deeper dive, check out SP vs BSP in greyhound betting explained.