I'm not a gambler but let's say you put down "DUBS to beat MAYO"
And the men lost but the women won can you still claim your win as it never stated the men or women???
I'm long out of the gambling game, but Yes bookies do have set and printed rules on ambiguous bets and as John M stated the price taken often clarifies which team you are betting on. However there is further rules which state that if no price is taken or event stated, certain sports take precedence over others, as in Horse racing would always take precedence over everything else, as in if a horse called 'Schumacher' was running in the 3.15 at Kempton and if a driver called 'Schumacher' was in the Grand Prix on the same day and a punter had a bet on 'Schumacher' stating no price, time or event, then horse racing would be given preference.
Ambiguous bets in general are a Minefield, no bookie could ever cover the rules on the amount of ambiguous bets being offered, the simple rule fer me when I was in that business was to pay de Kount on his bet and then bar him.