Well first of all do not let the opponent build 2 and only take 1 in year 1 :)
That got me some real pressure on you in austria, and on the long term you had no chance...

for more strategies and insight to GvI pm me, I don't want to lose against all because i told them :p

Ah and in most of the 1on1's you need a bit of luck in some "guessing" situations...

I am good with the specific tactical situations. I am good with guessing moves and choosing appropriate actions based on that. Just the overall strategy is tough for me.

Ok here I go.
Analizing the Classic layout, playing one country each. Some ideas can be used for other variants.
You will usually get 3 home SC's. You will have to get to 18 as soon as possible, ideally it is:
1901, 6 SC, 6 units, 1902, 12 SC, 9 units, 1903, 18+ SC, 12 units.
As you can see, the growth can be very very fast, and if you do too well, at the end you may not be able to build enough to have as many units as SC's you have.
But if you don't build enough the first year, it becomes a real big problem. Imagine you get only one build and then continue perfectly: 1901, 4 SC, 4 units, 1902, 8 SC, 7 units maximum, and your opponent is too much bigger for you.
Much worse is when your opponent captures one of your home SC's, preventing you to build. Even if you get the rest of it perfect: 1901, 5 SC, 5 units, 1902, 10 SC, 7 units maximum, only for not having your third home SC.
So, first rule is, above all, ensure 1901 and 1902 highest builds possible. Only reduce it if you can assure 100% that your opponent's builds will be reduced by the same amount or more. Do not think of further tactics that require the sacrifice of the first builds.
Second rule, try to prevent the other power to build, and getting any of your opponent's home SC is devastating.

Continuing with that.
On 1 vs 1, you usually have different kind of neutral SC's. There are the ones that are behind you (such as Spain and Portugal if you are France, I consider them "the easy ones"), the ones between you and the other power, and the distant ones (such as England and Turkey, depends on the variant.
I usually try to get my first 3 additional SCs from the ones between me and the other power (much better if it is directly an enemy home SC, of course). When I get the three builds, then I send some of the new troops to the back to conquer the easy ones.That is because if you do it the other way around, you will have the enemy at your doors in 1902. It is very rare if you can maximize your builds without using the easy SC's in 1902.

Fleets.
This is usually a tough call. Ideally, your opponent forgot about them, and with only one or two in each Sea area (northern seas and Mediterranean) it is enough to get all you need.
But if you send one fleet against two or three opposing fleets, you usually find that it was a very bad investment, because he got all the SC's, and took away the ones you wanted, and you couldn't do nothing about it.
So an acceptable policy would be that if your opponent send too many fleets to one area, don't bother to send anything, and let him harvest SC's with an excess of unnecessary fleets. For example, against Italy, you may want to block his exit of the Mediterranean and forget about all the southern SCs. At the same time, if you decide to play Italy maximizing fleet production, you will want to get out of the Mediterranean as soon as possible.

in addition to the last thing said, it's sometimes a good idea to exchange a SC for a further sea mvement. But try to do this only if you have 3 builds already assured, or if you're ahead of your oponent in builds.
Example, being italy, on year 2 it may be profitable to you to move fleet nap->thy->wes instead of tunis (privided you moved nap->ion->gree). That way you can get faster to MAO (key).

Also, this kind of games can get very slow and psudostalematelines can be stablished. Try to think ahead when positioning your units, never do just hold if you can move to another location to outflank your enemy, or be prepared to outflank him. A rather unuseful movement in year 3 can have it's profit in year 6, just because of a slightly better position (the butterfly effect)

Luck.
These variants have much more luck involved. First of all, there is no diplomacy, as you have only one enemy and you cannot change that (of course, if you can convince him to help you, my congratulations). You may want to talk, but you should play as if he never said nothing to you.
Your troops will clash very soon, and you may get a lot of situations were you have two alternatives, and the success is linked with two similar alternatives from the other player.
For example, you have two options, A and B. You opponent can play C or D. If he plays C, A wins and B loses, but if he plays D, A loses and B wins. There is absolutely nothing you can do about it (neither your opponent. It is good for these situations to study some game theory (very simple math, many books about it). But at some point, you may come to a redundant cycle. For example, the case before, maybe C is just a better move than D. Therefore, you opponent should play C, and then you should play A. But your opponent may also preview this, and so he can play D, knowing that it is not such a good move, but it ruins A. Then you should play B... or not? There is no way out of it.

That's it for now, I have not been very successful in my 1 vs 1 games so far; although I did better on the old site. Maybe I didn't put too much effort on them either, or maybe I just got it all wrong.
Someone could speak of other 2 players variants. I don't like the combined countries variants (Frankland vs Juggernaut or such) as it is like starting to play at 1902. I also don't like the symmetric variants, as even if there is a "perfect tactic", you either follow it or play against it, and there is usually a lot of luck involved (luck such as my previous post).

Very interesting. I always tried to think about a logical stalemate lines and try to race to these. But I guess I should do middle and then try and work to the corners.

Also, I guess there are certain places that are easier to stalemate than others. For instance Sev will likely always be possible while Spain may get sealed off.

well depends on the map, take the civil war for instance the south can be more easily attacked than the north can

first of all, thank you Jimbozig for this very interesting post: I think this is what the forum is for!!!

my tips:
- be aggressive: occupy lands as fast as you can, specially SCs. anyone can get Tun or Nor sooner or later, but who owns Bud Vie Mar Mos..... has more chances to win
- reach key spots before your enemy: as said before, the best way to break a stalemate line.. is not allow your enemy to set it up! try to have some units behind the enemy line, and your chances to win will double!
- try to corner your enemy, and if possible force him to keep his units in his own SCs. this is lethal for any power.
- tactics does play a big role! (I know you don't need advises on this subject as you're very good, but I wanted to be complete)

as a side note, I don't think luck is involved as much as most think. educated guessing is not luck. anytime you can do better than random guessing hoping for the best..
@ Benibo in this respect, I disagree with your idea about the symmetric variants: luck plays a minimal role in my opinion.

omg lmao! :)
(of course, if you can convince him to help you, my congratulations). <---- EPIC!

I agree with Tadar, Lepanto is a bit like chess, and you can't tell me chess is a luck game because it's symetric? :)
But I also agree, that in some situations "luck" is needed, because there is situations that you just have a 50/50 chance to guess right: "will he try for venice, or can I let it open?" if you cover it and he does not move in you can't build... if he moves in and you don't cover you're screwed... ;) both is bad what is worse? :D

but this is not luck! you have to assess the best move for you, and try to think as your opponent would, basing upon his style in that game or in previous ones.. it's a mind-game, not a luck-game!

My main aim is to get the SC's as far away from my home centres as fast as possible, and then get the close ones later. For instance, on France vs Austria, as Austria, I could move Bud-Gal-War 1901, and then War-Mos-STP 1902. Later I could then go back and grab Moscow, but i've got the one France can get (by fleets...he's unlikely to convoy to STP anytime soon)

RoxArt, you cant compare this to chess, because in chess you have one turn to move, then your oponent, then you again, and so on. Here, the moves are simultaneous. In chess, you never have to guess, or at least, is not the same kind of "guessing" that here. So pseudo-luck is indeed involved.

Re: luck - some guesses I believe are luck as well. kind of like rock/paper/scissors or something like that.