Sleeping Dogs: Definitive Edition

As far as I can tell, cockfight wins are a random event, so your best bet is to save before you bet on the cockfights. Take about $500k to the Kennedy Docks, where the minimum stakes are $50k and bet. Once you win, you can reload your save if you have lost money and keep the achievement. Unfortunately, it's hard getting the gold gambler achievement just playing mahjong, but at least there's a clear winning strategy on that game.

Hey people,

This post will be mainly for winning 1 million on bettings to get the gold award.
So it's true that the fights are completely random but with a bit of good guessing and luck on your side, you could get a few wins in a row.

It's better to leave this achievement until you have the apartment in the same part of the city where the 100k cock fights bets are held, this is so, if you lose, you can reload your save and quickly drive back there, as you reload in your apartment each time.

Why do you need to reload you ask?,
well, saving after every fight is not just to increase your money each time, but also each loss you get, takes off from your gold score.
For example, lets say you've won 500k so far on betting, if you lose 100k on a bet, it'll take you down to 400k on the gold award, so in order get 1 million from gambling, you need to win 10 bets in a row at 100k each.
This is why saving after each successful winning bet and reloading after a lost bet is the way to go.

I wrote down all the fights I had and the wins/loses to each fight.
Some fights were random each time but some were almost guessable to the same winner, depending on how many fights they'd won previously, which differs.

Guk hei 1 V dou gai an 4 (dou gai an is a good bet)
Guk hei 0 V chow ti 2 (chow ti is a good bet)
Guk hei 1 V huo yuanji 0
Guk hei 0 V sun tzu 0 (never fought)
Guk hei 0 V Leung kan 0 (never fought)
Sun tzu 1 V don gai an 1
Sun tzu 0 V chow ti 2 (chow ti is a good bet)
Sun tzu 3 V huo yuanjia 1 (sun tzu is a good bet)
Sun tzu 0 V Leung kan 0 (never fought)
Leung kan 1 V huo yuanji 4 (huo yuanji is a good bet)
Leung kan 2 V don gai an 0
Leung kan 4 v chow ti 1 (Leung kan is a good bet)

(last 3 never fought)
Chow ti 0 V don gai an 0
Chow ti 0 V huo yuanji 0
Huo yuanji 0 C don gai an 0

my stats
28 played - 14 wins -14 losses.

there are some good win estimates that i have found however, it's still random so they are not sure things.
Good luck everyone and i hope this helps you.

please let me know and comment if you want to add your matches up to help with the statistics.

Found this on steam guides, I bet max bet in Kennedy docks and got it first try. Here its copy pasted good luck.

***First I'd like to note that this guide is not 100% accurate and it is based on loose observation and taking notes while trying to get the "Gambler" challenge done. The bird can sometimes be beaten even with odds on your side for example when your bird starts running outside circle you most likely going to lose that round. There isn't definitive guide to win 100% of cockfights, it's pure RNG. Might not work with Definitive Edition ***

Breeds:
There are 4 breeds of birds: Croad Langshan, Jersey Giant, Rhode Island Leghorn and Buckeye Brahma. Every breed represent different class in game which gives every bird unique stats. Using this "strategy" i earned myself 2 mil HK $.

Croad Langshan is Striker;
Jersey Giant is Grappler;
Rhode Island Leghorn is Brawler;
Buckeye Brahma is Armed;

Strikers beat grapplers but loses to brawlers or armed;
Grapplers beat armed and brawlers but lose to strikers;
Brawlers beat strikers but lose to grapplers;
Armed beat brawlers and strikers but lose to grapplers;

Strategy

So, considering given theory the strategy looks like this:

Croad Langshan (striker) will beat Jersey Giant (grappler);
R.I. Leghorn (brawler) will beat Croad Langshan (striker);
Buckeye Brahma (armed) will beat Croad Langshan (striker);
Buckeye Brahma (armed) will beat R.I. Leghorn (brawler);
Jersey Giant (grappler) will beat Buckeye Brahma (armed);
Jersey Giant (grappler) will beat R.I. Longhorn (brawler);

Hope this guide will help you to build a fortune.