It's almost certainly playing out of an opening book.
There is a move history, but you have to expand it.
There is a move history, but you have to expand it.
Though in this case, I think it's almost certainly a blunder, that line does not appear to be a well known opening.
It's not a serious opening though, it looks frivolous - could be played in simultaneous games, or in bullet chess for its surprise value etc.
If you optimize the opening book to include serious games only, you're unlikely to come across this line. http://www.chessgames.com/perl/explorer?node=98&move=2&moves...
Given the insame amount of opening theory research humanity has done by now, if e4 on the third move here was even remotely close to a clever sacrifice, chess community would have noted it by now.
Without one, they have only a second to come up with an opening, so it's no surprise if the result is weird.