At last! They have arrived and settled in Thunderpick (???) !
Combo aka Express aka Multi aka Parlay aka Accumulator
They have several names but all work the same - you combine multiple individual bets into one bet. Combining the bets gives you larger reward for winning, but you have to be right about every single result to win the whole combo. The larger the amount of wagers included in your combo, the larger the payout.
Implementing Combo Bets was the most common request amongst the community. It took us some time and we believe there's still room for improvement so we'll keep working on it over the next couple of weeks. You can find them under the COMBO tab (next to the OUTRIGHTS).
Feel free to check out the on-site survey and vote for what should be implemented next.