Here is what I found out.

http://imageupper.com/i/?S0700…..0181163121

Coincidence? I dont think so. At this very moment when this shot was
taken, community member HL CLOWN GW IS A CURSE was #50 and it was easy
to monitor as he was (in my opinion) starting a new block. Remember
those lines separating 25/25/25/25 ?

My guess is Valve tried to give us a nice puzzle to solve, when Drunken
F00l came to play, they had to change their system.

What is even more interesting is that community member ChrisFPS
[SuRƒ] who successfully "guessed" my red-marked second block got his
wrench DELETED!

My guess – he was informed and he used his chance. and got punished.
Scary huh if you find some logic, get gold and get deleted!

You can see him here right now: http://www.tf2items.com/lists/….._wrenches/

I guess calculated wrench is more fair. But there is always high risk
that things go out of hand – business, trading, guys with tens on
wrenches. This is why I believe Valve originally planned it as a puzzle
with random elements.