Sadly it doesn't work anymore.

Simple but great extension. But no longer working again - probably due to Bet365 changing their website again. Any chance of a further update? Thanks!

As prev guy said it goes full screen for a second, then reverts. But then you can Ctrl and mouse scroll it bigger and it stays centered.

Thank you!!!

A fullscreen icon appears on Bet365. Once clicked it goes large but immediately goes back to the original size. However, due to its centre properties you can press Ctrl + to make it fullscreen without retracting back. The only downside is that you must use Ctrl - to reduce it. I like it. It's usable and shall be perfect when lying in bed.