After about 30 seconds of waiting (depending on the age of the machine) an arrow points or a best play starts flashing. As Diana said, we've had it mislead us (as happened to us at the Soaring Eagle M&G several years ago in the HL room). On a standard TD machine, anything over 35 credits should be considered. I think the best play indicator is just an average pay indicator and does not imply the machine knows the next offer IMO.