Moneyline = implied probability
Because a moneyline only resolves on the winner, the price translates directly into the probability the book is assigning. That makes moneylines the easiest market to reason about analytically.
Favorites, dogs, and break-even
A -150 favorite needs to win about 60% of the time to break even after vig. A +150 underdog needs to win about 40%. Knowing your break-even rate for any price is the foundation of disciplined betting.