Also I see that a lot of people are focusing on the choice scarfed variant. Ever think what happens when a ditto user just allows the enemy to set up, kill whatever he has out, and send his ditto in without a choice scarf to turn the whole thing into a crapshoot? that kills any and all the strategy and planning the setup sweeper user implemented to even setup in the first place, and at the decision of a speed tie, it's win or lose 50/50. Sure it maybe a "noob" reckless tactic to do that, but it's still possible. Same way spamming fissure is reckless but "cheap".
Basically, the essence of and philosophy behind using a setup sweeper is made obsolete with ditto around. the setup sweeper sets up so that it can overcome certain obstacles through sheer stats etc.
Ditto seems pretty uncompetitive to me...
I think you're forgetting how shitty Ditto's HP is, meaning that the 50/50 kind of scenario you describe will usually end up in the pokemon that Ditto transformed into's favor. There's a reason 99% of all Ditto wear choice scarf, and it's that Choice Scarf gives the most consistent concrete advantage for Ditto switching into any random offensive pokemon.
Anyways, while I disagree with the sentiment of your post, I do have to say I want to hear a bit more about non-choice scarf variants of Ditto, since it seems like DW has shown by and large that Choice Scarf Ditto is fairly threatening, but fairly predictable. Additionally, I feel like Choice Scarf gets rid of Ditto's most threatening possibility against non-offensive forms of play - unlimited PP and up to 24 different moveslots possible in battle. I feel like with Choice Scarf, the only guaranteed kill is revenging Dragons locked into Outrage, but I've had trouble trying to find a non gimmicky item. Some things I've thought of and tested just a little bit in DW at one point or another:
Focus Sash - needs to be a lead unless you can keep rocks off, though does a great job of bluffing scarf if played right. Remember, most people will switch their boosted pokemon out of Ditto to a wall to absorb the brunt of whatever move you're unleashing and forcing you to switch out. An intact Focus Sash can achieve the same effect as Choice Scarf (revenging a boosted sweeper) while making Ditto a bit more a long term threat. Priority is a bit of problem for this but scarf can't really handle it too well either. This seems like it probably has the most competition with Choice Scarf as a viable item.
Macho Brace - Essentially Choice Scarf under trick room without the lockdown effect. The big problem is once Trick Room is over you're up shit creek without a paddle.
Red Card - Depends on Ditto surviving the opponent's attack, which especially in the case of boosting pokemon can be an iffy proposition, but this has probably had the most impressive results when used successfully. Still seems like a bit too much of a gimmick.
Leftovers - Most reliable item in the game kinda gives away everything about Ditto right off the bat and usually leaves him at a disadvantage to whatever he's copying@Leftovers because of the lower HP stat.
Salac/Custap Berry - Haven't gotten a lot enough use out of these, but used right these take advantage of Ditto's low HP to give basically the same effect as Choice Scarf.
There's probably some more interesting examples, but I just wanted to get what I had so far to get across the point - Ditto@Choice Scarf is reliable in that unless the opponent is holding Choice Scarf, he will always be faster than what he's copying, but the fact that people are always expecting choice scarf has made him a way too predictable threat. All the items above except for Leftovers can easily bluff scarf (and scarf could bluff them in turn if they became popular) to use your opponent's gaffe of trying to lock Ditto into a not very effective attack against them. Also, strategies like Tailwind, Trick Room, Paralysis/Burn Support and Dual Screens aren't copied by imposter either way and I've found are pretty effective at giving ditto an advantage even without copying boosts.
I mean seriously, this pokemon is more versatile in terms of what he can do in a single battle than Smeargle and Arceus combined if you give him the right support.
![GH[O]ST](/forums/data/avatars/m/69/69331.jpg?1413405016){kind=avatar}
