As long as there are big enough differences in odds between two bookies, there would have to be value in at least one of them, right? How to find in which side, that's the point

I think this is generally true, but in this case the 2 markets are quite different. It's actually possible for both bookies to be 100% sharp here and zero value, because of weird stuff in sport like "if player A scores, then player B is more likely to score twice" etc.

Book 1 is saying 56% No, 44% Yes on both players.

Book 2 is saying the chance of B>A is 1.35X the chance of A>B, whatever they may be.

Both books can be 100% sharp if these are the probabilities:

- | - | - | Player B Touchdowns | - |

- | - | 0 | 1 | 2 |

- | 0 | 19.58% | 24.67% | 0% |

Player A Touchdowns | 1 | 24.67% | 22.35% | 8.73% |

- | 2 | 0% | 0% | 0% |

Conclusion: there

*may* be value here just like anywhere, but only if you know more than the bookies. Yay for maths!