Ledger 8 pin number how hard in terms of entropy is it to guess?
With an 8-digit PIN, the number of possible PIN combinations is 10^8 (100,000,000), ranging from 00000000 to 99999999.

So you chance of just guessing the PIN correctly within three tries is about 1 in 33,333,333. So it is of course possible, but extremely unlikely.

Note that an attacker could perhaps increase their chances by eliminating some possibilities (eg, assume nobody would just choose 00000000 as their unlock PIN), and/or by making a more educated guess based on knowledge of the victim (eg their birthday is 19 Jan 1980, so try the PIN 19011980).

Entropy is often described in terms of bits. To find the total entropy, take the binary logarithm of the total number of combinations. This turns out to be 26.575 bits of entropy.