What about this new book for systematic type play? It presents playing a Hanham Philidor and Old Indian as both black and white. https://www.newinchess.com/side-stepping-mainline-theory
Opening Systems for White and Black

Indeed. I will always advocate learning mainline theory first and foremost when building an opening repertoire, even more so when trying to aggregate a bunch of openings into a "system" per se. Which of course involves learning & relearning particular relationships between them. Tweaking certain move orders to isolate positions one likes to play, being aware of favorable or unfavorable transpositons and properly evaluating possibilities from the inevitable deviations.

But then, for me and when I was mentoring, the question of instituting a basic universal opening system wasn't the main priority or even thought of. Every opening is evaluated by its own merits. The overall framework is the old cliche " win with white, draw with black". Of course with nuances. For me or my former proteges, a "system" consists of openings in harmony with our own style of play. Our personal approach and attitude in how we see the game. I personally dont subscribe to sister openings nor reverse opening on that principle. Others may have a different view and it may make sense; I'm just saying," be true to yourself". I once knew a player who was totally all in with playing c4/c5 white or black and he was pretty successful to a degree even if he wasn't up to studying opening theory. It was just his philosophy. And I admire that. He is in harmony with himself.

Hell, I even played the Bird, Latvian Gambit and the Dutch when I was younger (like 8 or 9 heh) and yeah, I carry those experiences around with me and will unleash it every now and again on a whim but obviously I outgrew my naivety. (disclaimer: I was actually forced to because of the growing sophistication of opposition). I've developed my own system of openings since then, not universal nor comprised of current trends, unorthodox, weird, obscure...just practical. In keeping with my own chess philosophy. It never goes out of style for me because it's always in harmony. Thank you for indulging me guys. Best wishes😉

Oh. Great forum btw. I really dig the various perspectives and intriguing arguments. Keep it going!👍🏼

Hell, I even played the Bird, Latvian Gambit and the Dutch when I was younger (like 8 or 9 heh) and yeah, I carry those experiences around with me and will unleash it every now and again on a whim but obviously I outgrew my naivety. (disclaimer: I was actually forced to because of the growing sophistication of opposition). I've developed my own system of openings since then, not universal nor comprised of current trends, unorthodox, weird, obscure...just practical. In keeping with my own chess philosophy. It never goes out of style for me because it's always in harmony. Thank you for indulging me guys. Best wishes😉
Are you going to share?

@Chicken_Monster, here 's an example, annotated by a clubmate, of a game where my slow system went wrong and I was lucky to escape with a draw against a lower-rated player. I am White.

FrogCDE: Yea, much lower-rated player. yeah the KIA does kind of lead itself to the building of tension with quick release I guess. In a vote chess game we are going to play the Hippo, which should be interesting.

I'm developing a system which features mainland 1.d4 , the ruy Lopez systems as black and the semi-slav.. I believe these are all excellent openings for winning chess

I'm developing a system which features mainland 1.d4 , the ruy Lopez systems as black and the semi-slav.. I believe these are all excellent openings for winning chess
That sounds like what I'm looking for, potentially. When you say "system" do mean a setup sort of like the London System? I hear the Semi-Slav (Meran) can be used as a setup/system. Would be interested in see it if possible.

I believe I read Susan Polgar learned using the Colle-Zukertort system at White, and was successful with it I was thinking of implementing it in some games.
Is that the "best" opening system for White? What is recommended for Black as a system? I'm not sure what she used for Black.

@Chicken_Monster, my opponent was much better than his rating suggested, as I knew from a previous game - one reason I was so cautious when playing him.

I believe I read Susan Polgar learned using the Colle-Zukertort system at White, and was successful with it I was thinking of implementing it in some games.
Is that the "best" opening system for White? What is recommended for Black as a system? I'm not sure what she used for Black.
??

@Chicken_Monster, my opponent was much better than his rating suggested, as I knew from a previous game - one reason I was so cautious when playing him.
So you don't usually play the KIA unless you are worried about your opponent? (Don't want to put words in your mouth.) What do you usually play? I don't think anyway reads much other than the main forum....

That was actually my only rated game with the Nf3 KIA. (I have played KIA against the French a few times.) I am basically an e4 player, but I get tempted by system openings from time to time, and have been through the Colle, the Colle-Zukertort, the Veresov, the London, Larsen's Opening and the Botvinnik English. It's not really because I'm worried about my opponents, more that I find the simplicity of the concept attractive - you just play the same way against everything! But my results have generally been much worse than when I play 1.e4.

Then you should play that guy again and try 1.e4, which is what you are suite to or is what you have practiced the most.. I have multiple opening repertoires in mind, from ambitious with a fair amount to theory, to safe system play I will use if I even enter a tourney....but I play a variety of openings for practice online.
@FrogCDE Any examples? Just using basic opening principles or playing a book opening and not playing a rigid system can still put off tactics and build tension until there is an explosion.