Computer4 is really excellent engine.it is fast and 0 wrong moves.i played with it and i lost in 10|10 game.You can watch this game on my profile.i played carefully enough.but i lost in first time.
Yes,it is very good but we can beat it.Only we mustn't resign to try.
Everybody must play with it becouse it is a very good practicer.
Playing with engine is better than playing with someone becouse engine doesn't do any careless mistake.
Finally , i want to add "impossible is nothing..!"