Do tries and line-breaks have to be involved?
I think so. Otherwise he's not really making a play, is he? More like he's attempting to.
Couldn't a playmaker simply create attacking plays (on a regular basis) without them leading to either tries or line-breaks? Or, as Garry Gutful said, a playmaker could be an organiser of the team's attack and therefore, in a sense, direct the team around the park.
Playmaking involved a specific set of skills that cause breaches in the opposition defensive line or tryline. Usually they are halves but many hookers, fullbacks, and even some centres and forwards are good playmakers.
As for steering the team around the park, or whatever you want to call it, that requires the ability to make decisions and communicate, but doesn't necessarily require the running, passing and kicking skills that lead to big plays. A bloke who passes at the right time to a better playmaker might be valuable (like IDG and plenty of other hookers) but they are not themselves playmakers. Not by the definition I (and many others) understand anyway.
I think defining 'playmaker' is like defining 'love' - everybody thinks they know what it means, but .......
It's like a vagina, I reckon. I couldn't describe one, but I would know one if I saw it. Probably.