This shows the performance of 7 coins' difficulty algorithms for 3800 blocks. Notice in the additional posts below that Masari's with the new WHM N=60 is doing better than the runner-up (Zcash) ever did in the past year.

I would like to investigate other coins with other algorithms. See please send me your coin data to include your coin here.

The "% blocks 'stolen'" aka "cheap blocks" aka "hash attacks" is "blocks suddenly obtained with a high hash rate as evidenced by fast solvetimes in excess of the expected fast solvetimes". It is approximately 2x the avg of 11 ST < 0.385xT, so it is like the converse of the other metric "avg 11 SolveTimes > 2xT".

"Delays" are "avg of 11 ST > 2.1xT" and the >2.1xT values are printed on the charts. The values are divided by 4. For example, an avg 11 ST = 3xT is 3/4=0.75 on the charts. A 3x baseline hashrate attack is also 0.75.

The average 11 ST includes a lot of logic to prevent out-of-sequence timestamps from throwing off the calculation for the two metrics.

See also
the best difficulty algorithms
how to choose N for the averaging window
methods for handling bad timestamps
introduction to difficulty algorithms