When I first started tracking my MMA wagers in a spreadsheet, I realized pretty quickly that half my early mistakes came down to not understanding the language — I was betting chalk without knowing that's what I was doing, and I had no idea what the vig was costing me on every ticket. This glossary covers the 12 terms that show up most often at any licensed US sportsbook, so you can read a line, evaluate a promo, and talk to other bettors without losing the thread. Availability of legal MMA wagering varies by state; check your state's status before signing up. 21+. Gambling problem? Call 1-800-GAMBLER.
What does "vig" or "juice" actually mean, and why does it matter?
The vig (also called juice) is the sportsbook's built-in commission — it's embedded in the odds on both sides of a market rather than charged as a separate fee. On standard MMA moneylines, that commission produces an effective hold of approximately 5–8% per side, meaning the book keeps somewhere in that range on every dollar wagered over a large sample. When you see Fighter A listed at -150 and Fighter B at +130 instead of the "true" break-even price, the gap between those two numbers is where the vig lives. Understanding it is the first step toward evaluating whether a line actually offers value.
- Moneyline
- A straight-up bet on which fighter wins, expressed in American odds format. Negative number = favorite (amount you risk to win $100); positive number = underdog (amount you win on a $100 wager). For a full breakdown, see How to Read UFC Fight Odds: American Moneylines Decoded.
- Chalk
- Slang for the heavily favored fighter on the moneyline — the fighter whose odds carry a large negative number, say -300 or steeper. Betting chalk means accepting a smaller return in exchange for backing the expected winner.
- Sharp
- A professional or high-volume bettor whose action can move lines. When sharps hit a number hard on one side, books adjust the odds to balance their exposure. Tracking which direction lines move — and when — is a useful signal.
- Line Movement
- A shift in posted odds driven by betting volume, sharp action, or breaking news such as a weight miss or injury. A line that opens at -180 and closes at -220 has moved significantly, and understanding why matters for timing your bets.
- Closing Line Value (CLV)
- Getting a better price than the final odds posted before the fight starts. CLV is considered a key indicator of long-term betting skill because closing lines reflect the most information the market has processed. If you consistently beat the close, you're making sharp decisions. Learn how to pursue it at How to Shop MMA Lines and Why Closing Line Value Matters.
- Parlay
- A single bet combining two or more individual legs; every leg must win for the ticket to pay. Payouts scale multiplicatively, but so does the sportsbook's edge — each leg added compounds the hold against you.
- Method of Victory (MOV)
- A bet on how a fighter wins: KO/TKO, submission, or judges' decision. MOV markets often carry juicier odds than the outright moneyline. See the full rundown in Every MMA Bet Type Explained — From Moneyline to Method of Victory.
- Over/Under (Rounds)
- A wager on whether the fight ends before or after a set round total, most commonly 2.5 rounds. Over means you need the fight to go past that point; Under means you need an early finish.
- Prop Bet
- Any wager on a specific outcome beyond the outright winner — for example, "fight goes the distance YES/NO" or whether a fighter lands a takedown in a given round.
- Live / In-Play Betting
- Wagering placed after the fight has begun, with odds updating in real time between rounds. Useful if you want to react to what you're actually seeing in the cage rather than committing before the first bell.
- Rollover / Playthrough
- The number of times a bonus amount must be wagered before you're permitted to withdraw it. If a book grants you $50 in bet credits with a 5x rollover, you need to wager $250 in total before those funds become cashable. Rollover terms vary by operator and by state, so read the fine print carefully before claiming any offer.
How do these terms connect when I'm actually placing a bet?
In practice, the terms above work together on every ticket. You spot a sharp line move away from the chalk, decide to take the underdog moneyline before it closes, and later compare your price against CLV to judge whether the bet was well-timed — regardless of the result. If you claimed a welcome bonus to fund that bet, your rollover clock started ticking the moment you placed it. Getting fluent in this vocabulary doesn't guarantee wins, but it does mean you're reading the same information the books are and making deliberate decisions rather than guessing at what the numbers mean.
See also: Where Is MMA Betting Legal in the US? State-by-State Overview.