In reply to Removed Userphatlip:
As many people have said apples and oranges, bouldering only takes into account physical difficulty as generally bouldering is safe and has very little chance of a bad accident if you manage the bouldering pads. If you compare it to trad it is given 2 grades, a letter prefix for how mentally taxing the climb is and a tech grade for the physical difficulty such as hvs 5a this tells you the danger, character and difficulty of the route. If you think you're gonna be transferring your bouldering grade over to trad this is highly unlikely as climbing at your limit 1 or 2 meters above a pad with a small fall and perhaps a few cuts and bruises being the consequences of a mistake, but if youre metres above a dodgy IMP with the possibility of decking from 10 or 12 metres up, the consequences possibly being fatal on an E1 because you've messed up and couldnt get any gear in you'll soon find out what elvis leg feels like. You'll hear stories of people having near misses ive had one myself, and you should be aware that people who take trad seriously consider trad climbing completely different to any other discipline and do not try to start at the grade they think they can physically climb at, they usually start well in their comfort zone because an accident could put a rather abrupt end to their day. I guess all of that sums up the differences in a way because bouldering is fun and a leisurely activity with room for error with trad especially multipitch but the length doesn't really affect the grade however peak district routes tend to be harder and shorter whereas mountain multipitch routes in the lakes or Wales tends to get higher grades for the reduced ability to retreat in unfortunate events so length does not affect the overall grade but it may lower the physical grade but up the danger hence the adjective danger grade would go from vdiff to severe for example
