If one of the LONGS does not Win, you lose just your Investment. If one of your SHORTS does Win, you could lose many times your Invesment. Sometimes it can pay handsomely to bet on a Longshot (LONG) if their Price is really low. Similarly, sometimes it can pay handsomely to SHORT a favourite if their Price was really high (say, 23.00) - you would LOSE 2.00 if they Win but would gain 23.00 if they do not Win. The ROTO employs the same strategy for all the Categories - it all depends who or what is in the respective Categories and who you think the Winner will be.
For the record, the ROTO was 34/36 in the NominOptions with the YTD Port (botched BZEIT & JWEAV - good for a 1.9 MILL Profit.