Not all train companies offer reservations - in fact I don't think I've ever had a reservation on a Manchester-Sheffield train. One time I did resulted in a horrific journey coming back from Preston a few years ago on a hot August day, had seats reserved from Manchester back to Sheffield but the carriage that they were on didn't even exist! Hate that journey, always rammed, and will be especially bad on Sunday as they never seem to take big events into account - which is why I'm driving on Sunday.