Backing at 1/50 and Laying at 50/1? DO NOT GO BUST at extreme odds

Most of the real value on the betting exchanges — especially in big tournaments like the World Cup — sits on the lay side. That can feel completely backwards at first. Backing a 50/1 or 100/1 shot feels exciting and “normal.” Laying the equivalent at 1/50 (or shorter) feels scary, even when your numbers say there’s an edge.In this post (and the video below) I explain exactly why so much of the edge lives on the lay side, how to handle the variance and correlation that comes with player props, shots, cards and first goalscorer markets, and – most importantly – how to size these bets properly so one bad run doesn’t send you broke.

A Key Kelly Equations (for Exchange Betting) For Value Backs

 

For Value Lays

We use a very conservative 1/20 Kelly (0.05) in these correlated player markets because 15–20 bets in the same game can (and do) all go wrong together. Tiny edges are still edges — but only if you survive to bet another day.

Why Laying the Short Stuff Makes Sense

 

Recreational money loves big prices. Most would put £50 on 20/1 to win 1000/1 – but very few people will ever lay £50,000 to win £1,000 at 1/50, even when the numbers are in their favour. The result? The lay side of many player props, shots on target, cards and first goalscorer markets is often where the soft prices live.

In the Brazil vs Japan example in the video, we show a typical market where value on 16 out of 20 players is to lay in the first goalscorer market. Because it’s a shared liability market (only one player can score first), you can lay several of them and your maximum loss is still just the highest single liability. That changes the risk profile dramatically compared with laying “anytime goalscorer” or “2+ shots” where multiple can hit.

The Correlation Problem (and Why We’re So Conservative)

 

Here’s the bit most people miss: these bets are not independent. If the match finishes 0-0 with no shots, almost every lay in that game wins. If it turns into a 5-4 shootout with cards flying, a all of them lose together.That’s why Kelly (or even 1/4 Kelly) is dangerous here, and why we recommend 1/20 Kelly as a sensible starting point for these player-prop-style markets. The spreadsheet below bakes that in and lets you adjust the fraction yourself.

Player Liability Sheets

 Below are the full pre-kickoff player liability sheets for Brazil vs Japan and Germany vs Paraguay. You can see exactly which players were value to lay (and the occasional back) according to the model, along with the closing exchange prices and recommended stakes. 
Note not every price will have been available to the full liquidity. Often in exchange betting we find we have to take a spread of prices, or withstand partial trades. Note how small some of these bets are. Some, such as Rayan Vitor FGS, will not be worth the time it takes to place.

Free Download: Kelly Staking Calculator Spreadsheet

 
I’ve built a simple, practical spreadsheet so you can add your own value backs and lays and instantly see the recommended stakes/liabilities.
Download it here: Click here
What’s inside:
  • Yellow input cells for your bankroll and chosen Kelly fraction (default 1/20)
  • Easy table to add as many bets as you like
  • Automatic calculation of Full Kelly, recommended amount, edge, and whether it’s a back stake or lay liability
  • Pre-filled examples from the video
  • Works for both backs and lays on the exchange
Just enter “Back” or “Lay”, the decimal odds, and your estimated probability — everything else calculates itself.

Watch the Full Video

The video that goes with this post walks through the Brazil vs Japan example in detail, shows the numbers live, and explains the staking logic step by step.

Watch our FREE Value Betting Video-Course here: 

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