Bloons Wiki:Monkey Race/Appendix

Where [Current] is your monkey's current energy, and [Prerequisite] is the energy required for 100% success, the formula for chance of upgrade success is given by the formula:

[Current] / [Prerequisite] – 0.7 × (1 – [Current] / [Prerequisite])

Below are six tables, showing the respective probabilities for upgrade chances at different energy levels and upgrade prerequisites.

[Prerequisite] = 11

[Prerequisite] = 13

[Prerequisite] = 15 [Prerequisite] = 12

[Prerequisite] = 14

[Prerequisite] = 16