If you've spent any time online during baseball season, you've seen the ads — PrizePicks, Underdog, DraftKings — promising you can turn your fandom into cash with a few taps. Daily fantasy sports has gone from a niche corner of the internet to a multi-billion-dollar industry. But what is it, actually?
So what is daily fantasy sports?
Daily fantasy sports — DFS for short — is a contest where you pick a small group of real-life athletes for a single day or single slate of games. If the players you picked do well, you win money. If they don't, you lose your entry fee. That's the whole thing.
Imagine it's a Tuesday night in May. There are eleven MLB games on the schedule. Instead of betting on which team wins, you sit down and pick five hitters you think will rack up runs, hits, and homers. You enter a contest for $5. A few hundred other people enter the same contest with their own picks. When the games end, the entries are scored against each other, and the top finishers split the pot. That's a DFS contest.
The format has been around since 2009, when FanDuel started running one-day fantasy contests as an alternative to season-long fantasy leagues. DraftKings followed in 2012, and the two went on to dominate the early market. DFS exploded in 2018, when the Supreme Court struck down the federal ban on sports betting (PASPA). DFS and sportsbooks moved into the mainstream at the same time, and the lines between them have been blurring ever since.
You don't need to know anything about advanced stats to play. You don't need to draft a team in August and manage it for six months. You don't even need to watch the games — although most people do, because watching while you have action on the line is most of the fun.
How DFS differs from sports betting
The two get lumped together, but they work differently under the hood.
When you place a bet at a sportsbook, you're betting against the house. The book sets the odds. The book takes your money if you lose. The book pays you out if you win. The book wants to balance its action so it makes money no matter which side wins. That's why every market has a built-in margin called the vig.
DFS is contest-based. You're not betting against the house — you're competing against other players. The operator (PrizePicks, DraftKings, whoever) takes a cut of the entry fees as their service fee, and the rest gets paid out to the winners. They don't care who wins; they make their money on volume. Structurally, it's closer to poker than to a sportsbook.
That distinction matters legally. Because DFS is a skill-based contest among players — not a wager against a house — it's classified differently from sports betting in most jurisdictions. As a result, DFS is legal in more states than full sports betting, including a few states where you can't legally place a single-game wager on a regulated book. The exact legal map shifts every legislative session, but the gap is real.
The mechanics also differ. Sports betting is usually pick'em (will Aaron Judge go over 1.5 hits tonight? yes/no) or moneyline-style (will the Yankees win?). DFS comes in two main flavors: pick'em (more on this in a minute) and salary-cap, where you build a full lineup of players whose combined salaries have to stay under a cap. You'll see both styles depending on which operator you use.
One isn't better than the other — they're just different products. Plenty of people do both.
The major DFS operators
Four companies dominate the U.S. DFS market right now. Each works a little differently, and the differences matter.
PrizePicks
PrizePicks is probably the easiest place to start. It's pure pick'em: each player on the slate is assigned a stat line (say, Aaron Judge has a projection of 1.5 total bases tonight), and you pick whether they'll go over or under. You build a slip of 2 to 6 picks. If they all hit, you win a multiplier on your entry. If even one misses, you lose the entry — unless you played a flex format, which gives you partial payouts when most of your picks hit.
PrizePicks also offers what they call "demon" and "goblin" projections. A demon line is set harder than the standard (Judge needs 2.5 total bases instead of 1.5) and pays more if it hits. A goblin line is set easier (0.5 total bases) and pays less. Standard lines sit in the middle. The system gives you a way to dial difficulty up or down within the same contest.
Underdog Fantasy
Underdog is also a pick'em product, similar in feel to PrizePicks. The main differences are in lineup sizes, payout structures, and which sports they emphasize — Underdog leaned hard into NFL and college football early on, while PrizePicks built broader sport coverage. Underdog also runs drafting-style contests called "Best Ball" that are closer to a snake draft than to pick'em. For DFS purposes, though, their pick'em product is the main draw.
DraftKings DFS
DraftKings is the older, more complex animal. Their DFS contests are salary-cap style: every player on the slate has a salary, and you build a full lineup — in MLB, two pitchers and eight position players — whose total salary has to stay under a cap (typically $50,000). You then enter that lineup into a contest, which could be a head-to-head against one other player, a 50/50, a small tournament, or a giant guaranteed-prize tournament (GPP) with thousands of entries and a top prize that can run into six figures.
The skill ceiling on salary-cap DFS is higher than on pick'em. You're not just guessing whether one guy will go over; you're optimizing ten players against a budget, accounting for player correlations, weather, lineup spots, and ownership rates among other contest entrants. The learning curve is steeper, but so is the edge available to people who put in the work.
FanDuel DFS
FanDuel runs a salary-cap product similar to DraftKings, with slightly different roster constructions, scoring quirks, and contest types. People who play one usually understand the other immediately. Most serious salary-cap players have accounts at both sites because contest selection — finding soft fields and good payout structures — is a real part of the edge.
What a contest actually looks like
Here's a concrete walk-through. You open the PrizePicks app on a Tuesday afternoon, ahead of an 11-game MLB slate.
- Browse the player board. You see every player in tonight's games with their projection lines. Aaron Judge — 1.5 total bases. Shohei Ohtani — 2.5 total bases. Bobby Witt Jr. — 1.5 hits + runs + RBI. You can sort and filter by team, position, or stat type.
- Make your picks. You decide Judge is going to crush a struggling left-hander tonight, so you tap "over" on his total bases. You think Ohtani is being given too generous a line, so you tap "under" on his. You add three more picks. Now you have a five-pick slip.
- Pick your entry. You choose $5 as your stake. PrizePicks shows you the payout if all five picks hit — call it around $100, roughly 20x your entry (exact multiplier varies by contest format and shifts over time).
- Submit. The contest locks at first pitch of the earliest game in your slip.
- Watch and wait. Over the next four hours, the games play out. Judge homers in the third — that's at least 4 total bases, easy over. Ohtani goes 1-for-4 with a single, under. And so on. Your app updates live.
- Get paid (or don't). If all five picks hit by night's end, $100 lands in your account, available to withdraw or play again tomorrow. If even one misses on a standard slip, the entry is dead.
A salary-cap contest on DraftKings is structurally similar — pick players, lock at first pitch, watch results — but instead of over/under picks, you're scoring your lineup against everyone else's, and the top finishers split the prize pool.
Why people play
The short answer is that DFS sits at the intersection of three things baseball fans already love: research, strategy, and stakes. You read about matchups anyway — Tuesday night's Cardinals-Brewers game, what the rookie pitcher's slider looks like, who's hot at the plate. DFS gives you a way to convert that knowledge into something with consequences attached.
It also makes random regular-season games more interesting. A Tuesday in May between two teams you don't follow becomes appointment viewing when you have action on three of the hitters. People who play DFS often say their baseball viewing went up significantly once they started.
Entry costs are low compared to most forms of gambling. Contests starting at $1 are common; $5 is the most popular stake on most platforms. You can play for the entertainment value without putting real money at risk.
One honest note: most casual DFS players lose money in the long run. The operators take a cut of every contest, and a small group of sharp players take a disproportionate share of the winnings. If you're starting out, treat DFS like any other entertainment expense — an amount you'd happily pay for the fun and engagement, not a way to make money.
How RunsLeft fits in
RunsLeft is built to give DFS players a structural edge: we surface "edge picks" each day where our model disagrees with the market line on a player. If our model thinks a player's line is mispriced — say, the market implies a 50% chance and our model thinks the real number is closer to 60% — that's an edge, and it shows up on our tonight's DFS edges page with the reasoning attached.
The picks are operator-agnostic. Whether you play PrizePicks, Underdog, DraftKings, or FanDuel, the underlying stat projections — total bases, hits, runs+RBI, strikeouts, and so on — are largely the same across operators. The page is designed so you can look at the edges and apply them to whichever app you're playing on.
Where to go from here
If you've never entered a DFS contest before, the cheapest, lowest-stakes way to learn is to enter a $1 pick'em slip on PrizePicks or Underdog. Pick two or three players, watch the games, see how the format works. You'll learn more from a single $1 entry than from a week of reading guides.
If you want to keep learning the mechanics and strategy before you put money down, browse the other articles in /learn. We're adding pieces on which props the DFS markets misprice most often, how the major operators differ on a per-prop basis, and how to think about bankroll management when you're starting out — written in the same plain-English style as this one.