Alex didn't have a break average of 26 (which I imagine would be pretty good). The 8 numbers you averaged to get 26 were the 8 highest breaks he had in the four frames he played, not the average of all of his innings or scoring innings.
But that does raise an interesting question. How many points (how large of a "break") do the top snooker players average per inning in major events? I imagine it is a lot like straight pool, where points per inning may not tell much of a story if the game involved a lot of safeties.
This website breaks down all of the frame scores for every match at Qschool. Although there are some guys who posted 50+ breaks every frame, most frames are won in 2-3 innings. Typically 20, 30's and 40's.
http://livescores.love-snooker.com/Matches.aspx?t=13609
But as you get higher in the rankings, they make more frame winning breaks (60-70+). Lower in the rankings, players were typically making 30's and 40's with one or two 80-100 breaks. Every single player on the tour is at a century break standard, but there is a clear division between the top ranked players and mid-ranked players and bottom ranked players.
Using this website I calculated the average number of innings a professional player needs to win a frame about a year ago while I was bored. Top players averaged 1.8 chances if I remember correctly, where lower ranked players required 2.6 innings. This of course is from memory, but top players like Neil Robertson where making consistent 60-100 breaks and then other frames would make a 20 followed by a 50 to finish off the frame. Lower ranked players had more of the frames that required a 20 and a 50 or two 40's etc. They also had plenty of frames where they only made three 20's. It's worth noting that I was only looking at innings where the player had a decent chance score points, not including innings where there was clearly only 1-8 points available .
If the lower ranked players sound beatable, they aren't. At least not for most players. We also have to keep in mind that these guys often have great safety play, so not a lot of easy chances. It's one thing to make three twenties against a buddy who is leaving you reds over the pocket and quite another to do it against someone who leaves you tight on the cushion with no path back to baulk. Now imagine how hard it is to be making 50-100 against these guys.
So the answer regarding average breaks is that it varies. There is a huge variation between a top 16 player and someone just inside the top 64.