For all those who believe the Raptor D problems are just about "effort" and "earnestness" and a bunch players who allegedly just happen the worst in the history of mankind...take a look at slo-mo of a bunch of plays of the Celtics vs the Raptors on D.
The Celtics have smooth rotations where everyone knows where they're going and what they're supposed to be doing so when the opponent finally gets a shot its one of the shots the Celtics wanted them to have, often a lower probability chance or off-balance or whatever.
A lot of this stuff with the Celtics is not happening because of Garnett quality defending (even from Garnett) but because they're rotating to the right places at the right times and always positioned properly in relation to the basket and the other team. They know their assignments and they execute. A lot of the time it's pretty mundane, not highight reel defensive stuff. But man it works.
Even when things break down because of particularly good stuff from the opposition, they know how they're supposed to react to the breakdown - they know where to go positionally and what to do.
NBA basketball offense is about getting players out of position to create high probability chances...If you can't get players on the D out of position consistently then you're playing low probability ball - that's what the Celtics force teams to play and it wears you down.
The Raptors on the other hand look like the keystone cops in slo mo - running around smacking into one another off screens - they have no clue where they're supposed to be or what they're supposed to be doing - they rotate improperly and they are always being caught out of position. It's a joke. Look at it yourselves - I'd say it happens on the majority of plays - someone screws up and leaves a high probability chance - sometimes the opposition hits, sometimes they don't - but there's always a screw up.
They EITHER don't know what to do (i.e. the coaching system sucks) OR they know what to do and the coaches are not holding them accountable for screwing up. Either problem are the coaches fault. It sounds like it's both based on what the players are saying.
Man, some of this stuff is so obvious any high school coach could probably do a better job...