In general, on a single avocado tree all the open flowers will be synchronised. That means they will be all functionally male or all functionally female.
The avocado pollen of one tree is compatible with itself and quite capable of pollinating its own flowers — known as self-pollination.
The avocado has a ‘complete’ flower, but with an unusual behavior known as ‘protogynous dichogamy’. The avocado flower has both functional male and female organs in the one flower, but opens and closes twice over a two-day period — the first day as functionally female and the next as functionally male. Each opening stage only lasts about half a day.
The unusual flowering behavior is to reduce the likelihood of self-pollination occurring — by minimizing the amount of own-pollen about when female stages are receptive.
So while self-pollination is possible it appears to take the fun out of functionality.
~Just L (NaPoWriMo, April 22, 2017)