....and that's the key; if I may jump in. 'If you're good enough'. So many people like to say 'aikido doesn't work, because you can't do such-and-such', glossing over the fact that it takes practice - lots and lots of lovely practice - to respond instantly in the right way. Just learning a technique is not enough; you must commit it to the subconcious; so you can do it without thinking.
Sorry; this really belongs on a different thread; but I had to seize the moment.