'SP In Play' works in the same way as Keep In Play except that the unmatched bet's odds will be converted to Betfair SP price rather than the original odds that were used when the bet was initially placed.

Please note that if your SP bet is a lay bet then your bet must have a minimum liability of 10 GBP or the equivelant in other currencies for it to be accepted by Betfair.

To read more about Betfair SP please see http://promo.betfair.com/betfairsp/FAQs_theBasics.html