By Christian Hayes 
Why the favorite vs underdog framing matters in esports betting
When you tune into an esports match or open a betting board, the first thing you’ll notice are the odds and a fairly clear favorite and underdog. That framing isn’t just for drama — it compresses a lot of information about team strength, recent form, map advantages, and market expectations into a single price. Understanding that shorthand helps you judge whether a price is reasonable or offers betting value.
You should think of a favorite as the team the market believes is more likely to win. An underdog carries a lower implied chance of victory but pays more if they pull off an upset. Knowing why the market ranks teams this way gives you context for making smarter decisions: are you backing a favorite because they’re truly superior, or because the public likes them more?
How odds translate into implied probability and payout
Odds exist in several formats — moneyline (American), decimal, and fractional — but they all represent two things: the implied probability of an outcome and the payout you would receive. You can convert any odds into an implied probability to compare the market view with your own estimate of a team’s chance to win.
- Decimal odds (common in Europe): multiply your stake by the decimal to get total return. Implied probability = 1 / decimal.
- Moneyline (American): negative values (e.g., -150) indicate the favorite; positive values (e.g., +200) indicate the underdog. Convert to implied probability with simple formulas based on sign.
- Fractional odds (UK): show profit relative to stake (e.g., 3/1 means you win 3 for each 1 staked); convert to implied probability via denominator/(numerator+denominator).
By converting odds to implied probabilities you can test for “value”: if your own assessment of a team’s chances is higher than the implied probability, the bet might be worth placing. Keep in mind bookmakers include a margin (the overround) so market probabilities will sum to more than 100%.
Early factors that push a team into favorite or underdog status
Odds aren’t random — several predictable factors move prices before and during an event. You should watch for these elements when you form an opinion:
- Recent form: streaks and slumps often shift odds quickly because they reflect current performance level.
- Head-to-head and map pool: in games with varying maps (e.g., CS2, Valorant), a team that specializes on certain maps can be priced as a favorite even if their overall record is close.
- Roster changes and substitutions: a new player or a stand-in can dramatically increase uncertainty and move a team into underdog territory.
- Public sentiment and high-profile tournaments: popular teams attract bets from casual bettors, which can shorten their odds even if objective edge is limited.
Understanding these early influences helps you spot mismatches between the market and your analysis. Next, you’ll look at how bookmakers set those initial prices and how to identify situations where the odds give you a real edge.
How bookmakers construct opening lines
Bookmakers don’t pull numbers out of a hat — opening lines stem from algorithms, human models, and practical risk-management. At the core are power rankings and predictive models that combine team performance metrics (K/D, objective control, economy in CS2), map-specific win rates, recent roster changes, and contextual factors like travel, patch updates, and tournament stakes. Those inputs produce a “true” probability estimate, which the bookmaker then layers with a margin (the vig) and practical adjustments for expected public behavior.
Two important points about openings: first, they’re conservative estimates meant to attract balanced action, not necessarily the sharpest possible prediction. Bookmakers will often shade lines to account for predictable public bias — for example, shortening a popular team’s price because casual bettors favor them. Second, limits and market liquidity matter. High-profile matches attract heavy volume, so books keep tighter prices and lower maximum bets. Low-liquidity fixtures (minor tournaments, obscure regions) can have wider mispricings because the book is working with sparse information.
Reading line movement and finding value bets
Line movement is the market speaking. Early movement driven by large, informed bets (often called “steam”) usually signals sharp money and is worth attention; this is where professional bettors force books to reprice. Conversely, slow or one-sided movement after heavy public betting can create value on the underdog — the favorite’s odds shorten not because their win probability improved, but because casual money piled on.
Practical ways to use line movement:
- Compare books: Always shop multiple sportsbooks. Small differences in decimal odds translate to meaningful changes in implied probability over many bets.
- Watch closing-line value: The closing line (odds right before match start) is the most efficient market price. If you consistently beat the closing line, you likely have an edge; if you don’t, you’re probably chasing variance.
- Spot line drift: Late drift against a favorite (their odds lengthen) can indicate insider concerns, map veto issues, or roster uncertainty that leaked late.
- Use props and map markets: In games with map vetoes, match winner odds may be accurate while map-specific markets lag. Specialists who model map pools can find profitable edge there.
Live (in-play) odds open another avenue: momentum swings, pause breaks, and player form in-match can create transient edges. But live betting requires rapid decision-making and strict stake sizing — the markets move fast, and so should your discipline.
When favorite/underdog labels can mislead
Labels are shorthand, not truth. A “favorite” tag can hide fragile advantages — a weak map pool, a roster with internal issues, or a looming fatigue factor. Conversely, underdogs can be undervalued when public attention misses a favorable map draw, an overlooked strategic change, or a returning star player. Treat the favorite/underdog as the market’s headline; do the homework beneath it.
Focus on dissecting why the market placed a team where it did and whether your analysis disagrees. That disagreement is where value lives. If you find one, size your bet according to confidence and bankroll rules; otherwise, pass — the market is a patient opponent.
One practical final note: whatever edge you think you’ve found, protect it with sound bankroll management and humility. Variance is real in esports — even the best analysis loses sometimes — so size bets to survive losing streaks and keep records so you can learn what actually works over time.
Putting the favorite vs underdog framework into practice
Adopt a habits-first approach: develop a repeatable process for converting odds to implied probabilities, compare those to your own models or informed estimates, and only act when you find a clear discrepancy that justifies the risk. Use multiple books, track closing-line outcomes, and treat each bet as an experiment you can learn from. For a quick reference on odds formats and conversions, see Betting odds (Wikipedia).
- Convert odds to implied probability before deciding — never rely on the label alone.
- Shop odds across sportsbooks to maximize value and minimize friction.
- Focus on map- and prop-markets where specialist knowledge often creates edges.
- Size bets according to confidence and a clear bankroll plan; log results and iterate.
Frequently Asked Questions
How do I convert moneyline odds to implied probability?
For positive moneyline (underdog) use: implied probability = 100 / (moneyline + 100). For negative moneyline (favorite) use: implied probability = -moneyline / (-moneyline + 100). These formulas give the market’s percent chance before accounting for the bookmaker’s margin.
When is it smart to back an underdog in esports?
Backing an underdog is smart when your analysis finds reasons the market understates their chances — for example, favorable map vetoes, recent roster improvements not yet reflected in public odds, or mispriced live situations. Ensure the implied payout justifies the added variance and size the stake conservatively.
What indicates ‘sharp’ money moving a line versus public bias?
Sharp money often produces rapid, early movement and is followed by multiple sportsbooks aligning their prices, sometimes accompanied by reduced betting limits. Public bias typically shortens a favorite gradually and disproportionately on high-profile teams. Watching volume, timing, and whether multiple books react can help distinguish the two.