Nonce seems to be "random" enough, but few block analysis mention otherwise. Quoting from
https://bitcoin.stackexchange.com/q/24650,
Edited: Apr 18
I wrote a small program to collect some statistical data. From recent Dogecoin block #186,299 to #145,000 (the last mandatory update)
total 41,300 blocks
number of odds = 3,891 (9.42%)
number of evens = 37,409 (90.58%)
ratio of odd to even is about 1:10
Among the evens, the number of multiples of 256 = 35,106
85% of total
93.866% of evens
Update: 4/20
I recently also checked the nonces from block 552,780 to 253,898 of Litecoin.
totally 298,883 blocks.
number of odds = 42,963 (14.374521%)
number of evens = 255,920 (85.625479%)
Among the evens, the number of multiples of 256 = 225,746
75.529890% of total
I wonder if this could be a self-fulfilling prophecy? As in in the early days some large miners may have done some analysis and found that something like 60% of the nonces were even, which could totally be explained by statistical variance of course but still some large miners may have decided to just look for even nonces based on these findings. This obviously skews the statistics more in favor of even nonces, because more hashrate is only looking for those nonces now. After some time you may find that 90% of the nonces turn out to be even as more and more miners stop looking at odd nonces like some kind of perpetually reinforced superstitious bias. I mean statistics don't lie.