-HD mode. I haven't figured this one out yet (aside from some HDBypass shenanigans). Is it just for showing off, or a legimate way to guard break a defense and get and huge chunk of damage in? How important to ones game is it to have HD combos mastered?
-Run in game. I am clueless about that one as well it seems. Last time I was playing online I really had trouble to hit after run ins and also to defend against a run in (as if the opponent was always able to hit me first). Is there something I am missing? How does a run-in game plan look like? Mix up high and low with hyperhops, break and use special, fastest pokes / reversal?
- Is there a good resource for learning block strings creating pressure in the corner and escaping in the corner? There seem to be a ton of videos when it comes to combos but blockstrings not that much
Hey there! It seems like the other guys have answered most of your questions, so I'll just add my two cents regarding these topics.
HD mode is extremely important for most characters in the game. Very few characters have really bad optimized HD combos (King and Duolon). Remember that for any character you play, the combo you do should be geared towards METER OPTIMIZATION. This means, do the most damage as you can with a given combo starter and specific amount of meter. This will take some looking around/experimenting in training mode.
If you ever have full HD and your opponent has over 700 life, you will almost always need to do a meter efficient HD combo to kill them. Not being able to do this combo means that in these situations, you will not be able to win the match when you otherwise could have. This may be important or not, depending on how good/competitive you want to be.
When running, you can cancel your run into any normal attack or special move. However, you CANNOT cancel your run into a block. If you run and then hold back, there will be a couple frames where you are vulnerable. When playing online, even a couple frames of lag could make you very vulnerable while running. In terms of running in or rushing down, there is no set formula per se. What you should really be concentrating on is the movement and intention of your opponent. Remember to think critically, because telegraphing your offense with specific hop or attack patterns will not work in the long run. It may win you a couple matches here and there, but it won't make you a better KoF player.
When learning block strings, there are two things to consider:
1.) Is it safe on block? If not, what can it be punished by, and does my opponent know?
2.) Can it be easily guard cancel rolled and then punished?
Most of the time, your block strings will be a slightly modified version of your actual BnB combo that is safe on block and not easily guard cancel rolled. This will vary largely by what character you are playing.
I hope this helps! It's always great to see new players get into the game, and I hope you get a chance to play offline soon! In the long run, online play can actually hurt your KoF abilities.