How to track your sports bets: a betting log that works

Ask most bettors how their season is going and you'll get a feeling, not a number. "Pretty good." "Up a little." "Rough week, but fine overall." Memory keeps the big wins and the bad beats and drops everything in between.

A betting log fixes that. It's a simple record of every bet you place, and it turns "I think I'm doing okay" into a number you can check. It takes about 30 seconds per bet. This guide covers what to record, the three numbers to calculate, and how to use the log to find your leaks.

What to record for every bet

Use a spreadsheet, a notes app or a tracking app. The tool matters less than doing it every time, including the bets you'd rather forget. One row per bet:

• Date and sport
• Market: spread, total, moneyline, player prop, parlay
• Pick and odds in American format, like -110 or +150
• Stake in units, not dollars, so the log still reads right if your bankroll changes
• Sportsbook you placed it at
• Closing odds: the price right before the game started
• Result and profit in units
• One-line reason: why you liked it

Profit in units comes straight from the odds. A 1-unit win at -110 pays 100/110, or about 0.909 units. A 1-unit win at +150 pays 1.5 units. A loss is minus your stake. A push is zero.

The three numbers that matter

Once you have 20 or more settled bets, calculate these.

Record. Wins and losses. Easy to read, but it hides the prices you paid.

Units won. Add up the profit column. This is your real result, and it's why you track in units instead of dollars. If you use flat betting, units won is a clean read on your picks.

ROI. Units won divided by total units risked. It tells you how much you made per unit you put in.

Here's a worked example. You bet 50 plays, 1 unit each, all at -110, and go 28-22.

• Wins: 28 x 0.909 = 25.45 units
• Losses: 22 x 1 = 22 units
• Units won: 25.45 - 22 = +3.45 units
• ROI: 3.45 / 50 = 6.9%

You won 56% of those bets. The breakeven win rate at -110 is 110/210, or 52.38%, so you cleared it by about 3.6 points.

Why win rate alone can fool you

Win rate only means something next to the odds you paid. Say you bet 20 plays at +200, 1 unit each, and go 8-12.

• Wins: 8 x 2 = 16 units
• Losses: 12 units
• Units won: +4 units, a 20% ROI

That's a 40% win rate and a winning stretch, because the breakeven at +200 is 100/300, or 33.33%. Flip it around and a 60% win rate on heavy favorites can still lose money. The log shows you which one you are.

Track the closing line, too

Results are noisy. Price is not. The closing odds column lets you measure closing line value, which tells you whether you're getting good prices before the result is known.

Say you bet a side at -105 and it closes at -125. At -105 the implied probability is 51.22%. At -125 it's 55.56%. The market moved toward your side by more than 4 points of probability. One bet like that means little. If most of your bets beat the close over a few hundred plays, that's a strong sign your process is working, even through a cold month.

Be patient with small samples

Fifty bets feels like a lot. It isn't. A bettor who wins exactly 52.38% of the time at -110, which is breakeven, will still go 28-22 or better over 50 bets about 36% of the time. A good month can be luck, and so can a bad one. Treat your first few hundred bets as data, not a verdict.

Split the log to find leaks

The real payoff comes when you sort your log. Filter by sport, by market and by book, and compare units won and ROI for each slice. The kind of patterns a split can show:

• You're profitable on spreads and losing on parlays.
• One sport carries the whole record while another drains it.
• Bets placed right after a loss do worse than the rest.
• You keep taking -115 at one book when another had -105.

That last one is a pure price leak. It's fixed by line shopping, not by better picks.

Use your sportsbook's statement as a check

Your log is the main record, but your sportsbook keeps one too. FanDuel lists a Player Activity Statement among its self-service tools, which summarizes deposits, withdrawals, winnings and bets. DraftKings offers an account statement with a summary view you can set to a date range. Once a month, compare the book's total to your log. If they don't match, some bets never made it into your log, and it's worth finding out which ones.

A 10-minute weekly review

Pick one day a week and run through this:

• Settle every open bet in the log.
• Update units won, ROI and your share of bets that beat the close.
• Sort by market and sport. Note your best and worst slice.
• Check whether your unit size still matches your bankroll.
• Write one sentence on what you'll change, or "no change."

That's the whole system. It's boring, and that's the point. A log you keep honestly is the best research tool you'll ever own, because it's the only one built on your own bets.

The DARIMARKET board ranks every play by confidence and shows the price it needs to beat, so you can log the number you got next to the number you needed.

If it stops being fun, call or text 1-800-MY-RESET (1-800-697-3738). 21+.