There are a lot of (semi-)irregular openings around. They can easy lead to a quick defeat.
As J'adoube found out lately with the Benoni and the Benko gambit.
Since there are quite a few obscure lines adopted in my own repertoire I know it all too well myself.
Yesterday I encountered for the first time in my life the Grob (1.g4). It took me about 4 hours to find out what this opening is about. And although I don't know all ins and outs, at least I have an idea where the danger comes from. Boy, was I glad it is a correspondence game and not during Corus! In the end it is all pretty logical where white is after.
This story expresses clearly the problem at our level with opening study. If I'm catched off book, it takes me an enormous amount of time to analyse a position. If that happens OTB, you probably find yourself at the short end of the stick. Being worse or even worse. Or having a big plus in time trouble.
So if you learn openings by heart and play the main lines, the dirty work is done by grandmasters in the past. That's all very well, but there has to come a solution when you must leave the book lines. If that is at move 10, you have probably an acceptable position already, with most pieces developed. But if that happens at move one, as happened to me with the Grob, you have to a have something better than the knowledge "jeepers, he plays an opening that is not played at grandmasterlevel!".
So you have to develop the skill to analyse an opening position yourself. Preferably in less than 20 minutes. Correspondence play is a great opportunity for this.
Yesterday I played an obscure gambit myself, the Icelandic gambit.
The white player had clearly no idea where I was after, nor had he the skills to analyse a new opening position (although it was a correspondense game). He struggled for 10 moves only.
You can find the game here.
6 hours ago