After Amy's game where she was guaranteed a £15k win at 5-box, I thought I'd do some maths. Here are the probabilities that a 5-box board will guarantee the following wins, due to all of the lower amounts having been eliminated.

At least 1p guaranteed: 1 in 1 (100%)
At least 10p guaranteed: 1 in 1.29 (77.3%)
At least 50p guaranteed: 1 in 1.70 (58.9%)
At least £1 guaranteed: 1 in 2.26 (44.2%)
At least £5 guaranteed: 1 in 3.07 (32.5%)
At least £10 guaranteed: 1 in 4.26 (23.5%)
At least £50 guaranteed: 1 in 6.03 (16.6%)
At least £100 guaranteed: 1 in 8.77 (11.4%)
At least £250 guaranteed: 1 in 13.15 (7.6%)
At least £500 guaranteed: 1 in 20.46 (4.9%)
At least £750 guaranteed: 1 in 33.25 (3.0%)
At least £1k guaranteed: 1 in 57 (1.8%)
At least £3k guaranteed: 1 in 104.5 (1.0%)
At least £5k guaranteed: 1 in 209 (0.5%)
At least £10k guaranteed: 1 in 470.25 (0.2%)
At least £15k guaranteed: 1 in 1254 (0.08%)
At least £20k guaranteed: 1 in 4389 (0.02%)
At least £35k guaranteed: 1 in 26334 (0.004%)

Not interesting, but at least it's factual.

No, that is interesting in some way... I'm just not quite sure what