After my so and so experience with PES 2014, I just opened up PES 2013 and played some friendlies with national teams.
I was expecting more tbh I am a bit dissapointed.
I am playing the game as I am sitting on my childhood desk so my nostalgia peaks. Unfortunately that is not to be said about my appetite for the game.
sums up most of my revisits to all the titles since pes3 over the years..
here is my fresh retrospect ranking as of today of the very top of my head in short points, gameplay only, ranked from best to worst with short negative points listed:
1. pes3 corner header goals too often, some of the dribbling to easy
2. pes4 shots are weak and weird, pace a bit too much
3. pes6 ball physix (is a fix gameplay mod), still falls behind due to worse AI than the ones above
4. pes2008 corner headers goals too often, cheated penalties
5. pes5 weak COM attack AI, weak through balls, forced sidesteps, too many fouls, not enough cards, cheated too long put away ball from foot infront of goal
6. pes2011 lack of fouls, open midfield, lack agression, player individuality lacks when controlling player
7. pes2010 COM controlled CB own team lets striker through when both await cross, need to switch to CB manual to fix, no penalties, COM slide tackle glitch no foul
8. pes 2009 ball physix /glued-magnetic, keeper shot parry infront of goal easy tap-ins
from 2012 onwards too many issues to write here and all would be worse in rating starting behind 2009 on rank 9. (not joking

)
but id say its 18/20 > 14/15 > 12/13, did not play 16/17 and 19, 21 shouldnt be much diffrent to 20 since just an update