Betfair SP Explained: BSP vs Bookmaker SP

What Is Betfair Starting Price and How Is It Calculated?

BSP is generated by a proprietary algorithm that Betfair runs at the moment a race begins. Any bets left unmatched in the exchange's order book — either 'back' orders wanting the best available price or 'lay' orders willing to accept bets — are processed together at a single clearing price. That price is the BSP.

The algorithm finds the equilibrium point at which the volume of unmatched backs can be filled against the volume of unmatched lays, after accounting for Betfair's commission. No human intervention sets the number; it emerges entirely from real money placed by exchange users. This process is described by Betfair in their published exchange rules, which are available on their website and form part of their licence obligations under the UK Gambling Commission.

Because BSP reflects genuine supply and demand at the moment the race starts, it incorporates all late market intelligence — trainer reports, ground inspections, and last-minute betting activity — that is available just before the off.

How Bookmaker SP Is Set

Traditional bookmaker Starting Price is determined differently. For UK horse racing, bookmaker SP is calculated using the BAGS (Bookmakers' Afternoon Greyhound Service) methodology for greyhounds, while for horse racing it is derived from on-course boards. The official SP for horse racing in Great Britain is compiled by the Press Association (now PA Media) from the on-course betting market at the time of the race. Bookmakers pay out at this price when a customer has requested SP.

In practice, the on-course market has shrunk significantly over recent years, meaning fewer pitches are contributing to the price. A small number of rails bookmakers and on-course layers set the frame, and their quoted prices reflect their own book positions and liabilities rather than pure market equilibrium.

High-street and online bookmakers also impose their own margins when pricing races in advance. Their pre-race prices build in an overround — meaning the book totals more than 100% — so even when they settle at SP, the underlying price will generally reflect a market that has already been constructed to favour the bookmaker.

Why BSP Is Usually Bigger Than Bookmaker SP

The exchange model does not have the same structural overround built in at the point of price formation. Backers on Betfair are competing directly against layers; there is no single entity systematically pricing every runner to guarantee itself a profit margin on the book as a whole. As a result, exchange prices — and therefore BSP — tend to sit closer to true probability.

Academic research published in peer-reviewed sports economics journals has consistently found that exchange prices outperform bookmaker prices in terms of accuracy and size, particularly on shorter-priced favourites and in liquid markets. While specific percentage figures vary between studies and markets, the direction of the finding is robust.

For a punter, this means that a horse returned at, say, 5-1 bookmaker SP might well have cleared at 5.6 or 6.0 on BSP for the same race. Over hundreds of bets, that difference in base price is the dominant factor determining whether a staking plan produces a profit or a loss.

The Effect of Betfair's Commission

Betfair charges a commission on net winnings from each market. The standard rate for UK and Irish racing is published on Betfair's website and varies by customer according to their activity tier (the Market Base Rate system). New accounts typically face a higher rate; frequent traders may qualify for reduced rates.

Commission is deducted from winning returns, not from the gross BSP price itself. This means that when tipster services or proofing organisations quote BSP results, they should be clear about whether commission has been deducted. The industry norm among transparent proofing services is to quote results both before and after a stated commission rate, usually around 5% as a conservative standard assumption.

It is worth understanding that commission applies to net profits in a market, not to each individual winning bet in isolation. If you back a loser and a winner in the same market on the same day, only the net gain is subject to commission. This is distinct from how bookmakers deduct tax; betting duty in the UK was abolished for UK residents in 2001 under Finance Act changes, so punters do not pay an additional tax on their winnings.

Why BSP Is a Fair Benchmark for Tipster Results

When a tipster claims a profit, the result is only meaningful if it is achievable. Bookmaker SP sounds like a neutral measure, but in reality many bookmakers restrict winning accounts, reduce maximum stakes, or adjust prices on selections tipped by popular services almost immediately after publication. This makes bookmaker SP results increasingly theoretical for successful tipsters' followers.

BSP is universally accessible at the stated price regardless of stake size up to the available liquidity in the market, and Betfair cannot restrict a customer from backing at BSP in the same way a traditional bookmaker can limit an account. The UK Gambling Commission's licence conditions and codes of practice do not currently prohibit account restriction by bookmakers, but Betfair's exchange model means the BSP mechanism itself remains open to all.

For these reasons, the majority of independent proofing services — including the Tipster Proof community and similar organisations — use BSP as the default price for recording tipped selections. It is verifiable, time-stamped, and not subject to individual bookmaker pricing decisions made after a tip is published.

Practical Checklist: Using BSP Effectively

Before placing a bet at BSP or using BSP results to evaluate a tipster, work through the following points: • Confirm the tipster's results are proofed to a recognised independent service, not self-reported. • Check whether quoted profit figures are before or after Betfair commission. • Note the sample size — a minimum of 500 bets over at least 12 months gives meaningful data. • Look at the strike rate and average BSP together; a high BSP on winners can flatter a poor strike rate. • Verify that tips are issued before the market opens for Betfair SP to be a replicable price. • If you use a different exchange or a betting broker, check their equivalent starting price mechanism and any additional charges. • Set a defined staking plan before you start and record every bet yourself independently.

BSP for Markets Beyond Horse Racing

Although BSP is most associated with UK and Irish horse racing, Betfair operates a BSP mechanism across a number of other sports, including greyhound racing and, in some markets, football. The liquidity in these secondary markets is lower, which means the BSP price can be more volatile and less reliable as a reflection of true value.

Tipsters operating in greyhound or lower-tier football markets should be assessed with this in mind. Thin liquidity means a single large bet placed at BSP can itself move the clearing price, making large-scale replication of results more difficult. Always check the average matched volume in the specific markets a tipster covers before assuming BSP results are straightforwardly replicable at scale.

Summary

Betfair Starting Price is the most transparent and practically accessible benchmark currently available for evaluating tipster performance in the UK. It is set by the market, not by a bookmaker, and it is available to all customers at the published price without the account restrictions that affect traditional bookmaker SP.

Commission reduces net returns and must always be factored in when reading proofed results. Even after commission, BSP will frequently exceed bookmaker SP, particularly for selections in competitive, liquid markets. For anyone assessing a tipster's track record, insisting on independently proofed BSP figures — with commission stated — is the minimum standard that makes results meaningful.