Implied probability translates odds into a percent chance of winning. For example, -150 means a 60% chance, while +200 means 33.3%. You can calculate it using this formula:

Negative odds: -150 → 150 / (150 + 100) = 60%
Positive odds: +200 → 100 / (200 + 100) = 33.3%

Straight bets are single wagers on one outcome. Parlays combine multiple bets into one. Parlays offer higher payouts, but all picks must win for you to cash in.