Seth doesn’t have any good ways to beat both walk up/dash up and focus besides EX Sonic Boom, and that’s unsafe at certain ranges.
Versus focus:
[LIST]
[]EX Sonic Boom (add on standing fierce for more damage)
[]Super
[]Ultra
[]Sonic Boom + far standing fierce
[]Hyakuretsu (armor breaks)
[]Shoryuken hits twice up close to ‘armor break’
[*]SPD
[/LIST]
Versus Dash/walk up:
[LIST]
[]Far s.mk/s.hk
[]Far s.hp
[]Sonic Boom
[]Tandem Engine (unsafe from far away or if they jump at you)
[*]Cr.mk/cr.mp/cr.lp
[/LIST]
Backdash, backwards teleport, and jump back fierce are good at creating space. Obviously, walljump out of the corner.
Seth has some of the best anti-airs in the game. KKK backwards teleport versus crossups, shoryuken versus jump-ins, ultra versus jumping anywhere, s.hk and close s.hp versus crossups, and EX SPD versus safe jumps.
HP shoryuken has more priority, but lp shoryuken gets you a combo into stomps.
EX SPD, EX Shoryuken, HP Shoryuken FADC (for safety), counter-poke with cr.lp or cr.lk, backwards kkk teleport.
I play Seth in two modes: Runaway bitch and rushdown asshole. I run away until I get a chance to jump in or knock down, and then I apply mad pressure, two bars and ultra be damned (except versus Zangief, although I love to EX SPD him on his wakeup).
I have a thread somewhere in the archive about his reset mixups off of a dive-kick. Basically, Seth has a low he can combo into a knockdown (cr.lk or cr.mk xx sonic boom FADC hit-confirm), an overhead that lets him keep up pressure and gives you a reset if they try to jump (instant air headstomp and dive kick), a command throw (SPD), a shoryuken to punish them for pressing buttons during your strings, a great ambiguous crossup (j.hk), and a really safe runaway option (jump back hp). I know I just said a lot, but that’s basically Seth’s mixup game in a nutshell.
Seth’s runaway game is a type of offense too, relying on Sonic Booms and the threat of ultra to get them to chase you. Trying to set up anti-airs and pokes while running away gets them set on chasing you down so you can get away with an occasional walljump.
Seth does not have an optimal range. Seth can, and should, change up the range of the battle as often as possible. Once you’re in generally you want to stay close and apply pressure, but if you get pushed out you shouldn’t force your way in again. Seth has tools at every range, the tools are just different. If you stay at one range for too long you’ll get predictable and start getting pushed to the corner or eating damage. You need to learn when to run and when to rush. I disagree that Seth is better at long range in general. You only want to be at long range to get your ultra.
Zangief and Sagat have to be mentioned for their huge damage output. Knowing the Zangief matchup is huge to winning, even though it is in your favor. Really, just look at the tier list. All the matchups are important - you can’t win a matchup if you don’t know what’s up and the other person does.