Wagering, in NZ especially, is being drastically diluted by the policy of the TAB, which believe it or not is an arm of the Racing Board, saturating the market with (apologies) crap races. The TAB knows that people will bet on almost anything regardless of it's merits or otherwise and I consider it is very irresponsible of the Racing Board allowing their TAB arm to concentrate on taking all the lolly (people only have so much to spare on leisure) rather than channel it towards the local product which they themselves theoretically administer.
In answer to the question raised by Allan, the pacers final is the most lucrative but the trotters are not too far behind.