Okay, a few days down the road...
First, thanks for the links to the videos. That is a lot easier for me to understand.
I mentioned how I noticed I seemed to grab one card of multiple types. Basically, I was unfocussed, and obviously, that wasn't working. But that simple realization was a big breakthrough for me. Since I noticed that, I take a moment before committing to play to look the board over. During the opening stages of the game, I try to stick to one or two core cards, and then depending on how the game goes, branching out from there. It has made a world of difference.
I still have yet to be able to beat my son at the game, but that's largely because we can't play face to face that often with him in school. He prefers playing through Iso, but that's because he can use any of the cards in any of the sets. That puts me back on the defensive because I don't know that many of the cards yet. Once I've played with multiple card multiple times, I'll start to feel my way through them and improve.
Having said that, when I lose, it is usually a lot closer, and we are talking one or two points difference. This has also shown up on Goko bot play. I'm guessing here, but that breakthrough seems to have driven my win rate up past 75%. That's probably conservative. And again, when I lose, it's usually only by a few points. (On the flip side of the coin, when I win, I usually destroy the bot...60-65 vs 10-15 is a pretty good bet.)
I don't know why didn't notice my previous playstyle and how it was hurting me, but now that I have, I've seen big improvements. I may even be confident enough to play a few strangers online now...well, soon anyway. So look for me, I'll likely be around more often over there now.
Of course, the way my luck runs, I'll start to rise up the leaderboard on Iso, and that's when it will shut down. =)