I would say he played a great 1/3 of the match. Once he invaded Ukraine proper with a full on assault he misplayed by not continuing his slow game. I think him being 70, having possible health issues, and getting older played into him over reaching as he may have been wanting to get his great Russia/USSR reclamation done prior to aging out and not getting credit and to revel in his success.
If he had kept at his prior game of incremental growth and in his latest step had just declared the contested Donbas/Luhansk areas as being independent (and later annexed them), but not invaded for the entire region, then likely he would have had success and the world would have reacted similarly to when they took Crimea. That was my concern when this started is that if he did the small step like in the past that the world would do more limited sanctions and then ignore it as a local issue.
He overplayed his hand with a full on country invasion of conquest and then had the unfortunate need for a real army with real leadership instead of a an army trained to be overpowering thugs and bullies.