[Guest]

Maybe here you can find some answer:

http://www.ww2wings.com/wings/finland/finlandmain.shtml

as they say:
"The consensus is that the Finns were vastly superior pilots compared to the Soviets particularly in air-to-air combat situations. This was due in no small measure to the fact that the training of FAF pilots focused on air-to-air combat. Historians credit Finnish innovations in loose formation flying, aerial acrobatics skills and improved combat tactics for their enormous successes. The FAF fighter pilots consistently used the element of surprise as a major weapon."

So it seems that Russian planes never could definitively penetrate finnish air space!

Also interesting:
http://www.sci.fi/~ambush/faf/faf.html
...
and surely other sites I don't know...

If you bothered to read your own sources with a sound amount of criticism, you would know that Finnish airspace was penetrated on daily basis, and that many Soviet pilots never saw a Finnish fighter during the Winter war, manly due to their numeric superiority.

The FAF did concentrate all their effort on intercept missions, avoiding Fighter to Fighter engagements. If we look at the share numbers of victories on both sides, the finns lost nearly as many fighter aircrafts as the Soviets, so the majority of the Soviet air losses where Bombers, recon and transport planes.