Don't Try The 10k Betting Challenge

The 10k betting challenge is once again sweeping across social media, and I'm begging you not to participate. This short article will help you understand why, mathematically, this is the absolute worst way to make money betting on sports.

For those unfamiliar, it's a 10-day challenge, where you try to turn $10 into $10,000 by doubling your money each day. 100 percent of the previous day's winnings are then re-invested into the challenge.

I'll walk you through the basic math for this challenge - assuming we're an average bettor, and then I'll include the math behind the 10k betting challenge if we assume we are the caliber of a professional bettor. Finally, I'll discuss a lower risk alternative to the 10k challenge.

For The Average Bettor

The below chart outlines the general path for the 10k betting challenge. This chart assumes we are placing 50/50 bets as we try to double our money daily. The Survival Odds column shows the odds of surviving to the next day with your bankroll still in tact. We can see that after Day 1, we have a 1 in 2 chance of reaching Day 2. We have a 1 in 32 chance of surviving Day 5 and having $320 in our account. And we have a 1 in 1,024 shot at actually securing the $10,000 after Day 10. The Survival % column just translates those odds into percentages, so surviving through Day 7 should happen 0.78 percent of the time that we try the 10k betting challenge.

Put another way, 1,023 out of 1,024 times that we do the 10k betting challenge, we should expect to lose our money. And, this is assuming that we are optimistically hitting our +100 odds bets (50/50) at a 50 percent clip, when sportsbooks generally try to have +100 odds bets hit around 48-49 percent of the time. After all, the sportsbooks are a for-profit business.

Day	Start	End	Survival Odds	Survival %
Day 1	$10	$20	1 in 2	50
Day 2	$20	$40	1 in 4	25
Day 3	$40	$80	1 in 8	12.50
Day 4	$80	$160	1 in 16	6.25
Day 5	$160	$320	1 in 32	3.13
Day 6	$320	$640	1 in 64	1.56
Day 7	$640	$1,280	1 in 128	0.78
Day 8	$1,280	$2,560	1 in 256	0.39
Day 9	$2,560	$5,120	1 in 512	0.20
Day 10	$5,120	$10,240	1 in 1,024	0.10

For The Professional Bettor

Professional bettors may reach as high as a 60 percent hit rate on bets where the odds indicate it should be 50/50. If we assume that we have a 60 percent chance to survive each day, instead of 50, the odds do get much better ... though they're still incredibly daunting.

Instead of a 1 in 1,024 chance of making $10,000 in ten days, we now reach the promised land about once every 165 attempts.

Day	Start	End	Survival Odds	Survival %
Day 1	$10	$20	1 in 1.7	60
Day 2	$20	$40	1 in 2.8	36
Day 3	$40	$80	1 in 4.6	21.60
Day 4	$80	$160	1 in 7.7	12.96
Day 5	$160	$320	1 in 12.9	7.78
Day 6	$320	$640	1 in 21.4	4.67
Day 7	$640	$1,280	1 in 35.7	2.80
Day 8	$1,280	$2,560	1 in 59.5	1.68
Day 9	$2,560	$5,120	1 in 99.2	1.01
Day 10	$5,120	$10,240	1 in 165.4	0.60

Instead of the 10k Betting Challenge

This might sound obvious, but I wouldn't vary your individual bet size based on which day of the challenge you're on. For the 10k challenge, you begin by putting $10 on each bet. If you're fortunate enough to make it to Day 10, you're putting over $5,000 on a single bet, more than 50 times what you were risking per bet just a week and a half prior.

Below, I'll outline a much less risky game you can play. If you're obligated to play a betting game - I'd recommend exercising betting restraint and never forcing a play, but I do believe this thought experiment is a much safer alternative to the 10k betting challenge.

If you typically put $20 on each bet, that's what I would continue to do. As an example, let's assume that you place five $20 bets on Day 1. We'll also assume you win 60% of your bets - like a professional bettor, and all bets are +100 odds double-ups.

After Day 1, 100 percent of the remaining money is re-invested into $20 bets. So, if three of your five bets hit, you'd have doubled your $20 bets three times. Now, you'd have $120, as you made $40 three times. For Day 2, you'd place six $20 bets since your bankroll is now $120, instead of $100.

I ran 100,000 simulations of this challenge in R, and the results of the simulations are displayed below. After Day 10, we'll have turned our $100 into $620, on average. The Bankrupt % is the percent of the time we lose all our money from betting. Notice here that only about 11 percent of the time do we end Day 10 with no money. Whereas, if we had a 60 percent hit rate and did the 10k betting challenge, 164 out of 165 attempts we finish with no money (99.4 Bankrupt %).

Day	Start	End	Bankrupt %
Day 1	$100	$120	0.96
Day 2	$120	$144	2.95
Day 3	$144	$173	4.92
Day 4	$173	$208	6.51
Day 5	$208	$249	7.86
Day 6	$249	$299	8.92
Day 7	$299	$358	9.73
Day 8	$358	$430	10.50
Day 9	$430	$517	11
Day 10	$517	$620	11.44

I'd still suggest only placing bets when you believe you have a statistical/logical edge, but this is just about the safest way to execute some type of betting challenge where you're re-investing 100 percent of the previous day's winnings.

To summarize, don't try the 10k betting challenge. Your bankroll will thank me for this advice.