Soft lines are sportsbook prices that sit out of line with the rest of the market, usually because a book is slow to react or prices a market loosely. A soft line pays more than the market's fair price says it should, so it can be a positive expected value bet if that fair price is right. You find one by comparing a book's price with a sharper reference: a sharp book's no-vig price, the market average, or your own model.
How it works
Every price implies a probability. A soft line is a price whose implied probability is lower than your reference's fair probability.
To get a fair probability from a two-way market, remove the vig (the book's margin) from both sides:
fair probability = one side's implied probability ÷ both sides' implied probabilities added together
Then measure the soft price against it:
EV % = (fair probability × decimal odds − 1) × 100
Worked example
A sharp book prices a player's over 22.5 points at −120 and the under at +100.
- −120 implies 120 ÷ 220 = 54.55%. +100 implies 100 ÷ 200 = 50.00%. Together they add up to 104.55%. The extra 4.55% is the vig.
- The fair probability of the over is 54.55% ÷ 104.55% = 52.17%. That's a fair price of about −109.
- Another book offers the same over at +105. That price implies 100 ÷ 205 = 48.78% and pays 2.05 in decimal odds.
- EV: 0.5217 × 2.05 − 1 = 0.0695, or about +7%. On a $100 stake, that's about $7 expected on average across many bets like it, not $7 on this one.
The +105 is the soft line. It implies a 48.78% chance on an outcome the sharper market puts at 52.17%.
Soft vs sharp sportsbooks
A sharp sportsbook takes large bets at low margins and moves its prices quickly when informed money arrives. Because its lines absorb that information, many bettors treat a sharp book's no-vig price as the best available estimate of fair value.
A soft sportsbook is built for recreational bettors. It tends to carry higher margins, list far more props and specials, and limit accounts that win consistently instead of moving its lines on their bets. Its prices often follow the market rather than lead it, so they can lag after news breaks or the sharp market moves.
"Soft" describes a price more than a whole company. A sharp book can be loose on a niche prop, and a soft book can be tight on a main spread that draws heavy action. Judge each line on its own.
Why one-way and longshot markets stay soft
Some markets stay soft because they are hard to price and slow to correct.
- One-way markets. First touchdown scorer, anytime goal scorer and many player specials offer only one side. With no opposing price, there is no simple way to remove the vig, so books can build in large margins and prices spread out across books.
- Longshots. Small differences in probability become big differences in price. +800 implies 11.1% and +1000 implies 9.1%: two points of probability, but a 200-cent gap on the board.
- Low limits and thin action. Fewer sharp bets arrive to push a stale price back into line.
The same things that make these lines soft also make them noisy. A longshot can be priced well and still lose most of the time.
How to find soft lines
To do it by hand:
- Pick one market and collect every book's price for the same player, side and line. An odds screen saves the tab-switching.
- Pick a reference. On a two-way market, devig a sharp book's prices with the No-Vig calculator. On a one-way market, use the average price across books or a sharp book's price for that side.
- Compare the best available price with the reference, and put a number on the gap with the Expected Value calculator.
- Confirm the line, the market rules and the current price at the book before you bet.
On Unjuiced, Soft Lines (formerly Edge Finder) runs that scan for you. It looks for prices that sit away from the reference you choose under Comparing: the market average, Pinnacle or another book, the next best price, or one of your custom models. Sort by Edge %, which is how far a price sits from that comparison, and press a row to see every book's price and how it moved. The list opens capped at +500 so long shots don't fill it; change the cap in Filters.
Soft Lines works on one-way markets, where only one side is offered. Positive EV needs both sides so it can devig. For a full walkthrough, read how to use Soft Lines or see what Soft Lines includes. For the math behind expected value, see what is positive EV betting.
Mistakes to avoid
- Comparing soft to soft. A price that beats the average of several recreational books may only be less bad. Check it against a sharp reference too.
- Shopping for a reference. Switching comparisons until a bet looks good doesn't create value. It only changes the assumption you're testing.
- Trusting a huge edge. An outsized gap is more often a stale quote, a different line or different settlement rules than a real mispricing. Verify before you bet.
- Reading edge as a win chance. In the example above, the +105 over still loses about 48% of the time even if the fair price is right.
- Oversizing longshots. Edges on longshots come with long losing runs. Size stakes for that variance, for example with a fraction of Kelly.
Questions
What is a soft line in sports betting?
A soft line is a sportsbook price that pays more than the market's fair price says it should. It usually comes from a book that is slow to move or prices a market loosely, and you spot it by comparing that price with a sharp book, the market average or a model.
What is the difference between a soft and a sharp sportsbook?
A sharp sportsbook takes large bets at low margins and moves its prices quickly when informed money arrives, so its lines are a good estimate of fair value. A soft sportsbook targets recreational bettors, carries higher margins, follows the market rather than leading it, and tends to limit consistent winners.
How do you find soft lines?
Collect every book's price for the same player, side and line, then compare the best one with a reference: a sharp book's no-vig price, the market average or your own model. A price that implies a lower probability than the reference is a soft line. Tools such as Unjuiced's Soft Lines run that comparison across books for you.
Which betting markets have the most soft lines?
One-way and longshot markets, such as first touchdown scorer, anytime goal scorer and longshot player props. Only one side is offered, margins are large, limits are low, and fewer sharp bets arrive to correct the prices.
Is a soft line the same as a positive EV bet?
Only if the reference is right. A soft line beats your comparison price, and it has positive expected value only when that comparison is a good estimate of the true probability. That's why the choice of reference matters as much as the size of the gap.