Hello, sorry if this has already been done before, but I made two graphs for the number of eyes of ender for end portals.

This shows the probability of an end portal being spawned with any number of eyes of ender already filled. As you can see 1 eye of ender already in an end portal is the most common (with 10% chance per slot). The graph stops after 6 because the chances become super close to 0. The chance of 6 eyes of ender spawning in an end portal is already ~1 in 2000.

These numbers have been known for a while, but I also made this second graph that visualizes how many eyes of ender speedrunners should aim for (once in the stronghold).

As you can see, you are 100% likely to fill an end portal with 12 eyes of ender on you, since the end portal always consists of 12 blocks around it. If you only have 10 eyes of ender on you, that will only be a 34.1% chance of being enough to fill the portal (of course, assuming you are gathering eyes of ender before actually finding the stronghold to see how many you need).

There is only a 2.6% chance that 8 eyes of ender will be enough, so if you were to shoot for that, expect to do an average of ~38 runs before eventually finding a seed where 8 will be enough to fill, ~250 runs for 7 eyes of ender, and ~1000 runs for 6 eyes of ender.

I hope these reference visualizations will find you helpful.

wow I really like these charts congrats to you they must have took forever to make! good job!

I made a simulator for this kind of thing a while back, I'll just post it here because I don't know what to do with it:

https://end-portal-simulator.glitch.me/