Preferring a formula over a password manager is advice of dubious quality. Yes, a password manager may be a hassle to setup, but it offers protection under a wider variety of threat models.
E.g. using the BaseballRules!<word> formula for your passwords gives you decent protection from completely automated attacks with no feedback loop. But if a human intercepts just one of these passwords, then they can easily brute-force their way to any of your accounts that doesn't have some sort of 2FA. Not nice. And good luck remembering the special <word> for more than a handful of web sites.
Plus, xeroxing/printing your password list is also not as benign as it sounds. Any professional copying machines or printer typically includes some sort of non-volatile memory, that could be used to recover recent printouts.
E.g. using the BaseballRules!<word> formula for your passwords gives you decent protection from completely automated attacks with no feedback loop. But if a human intercepts just one of these passwords, then they can easily brute-force their way to any of your accounts that doesn't have some sort of 2FA. Not nice. And good luck remembering the special <word> for more than a handful of web sites.
Plus, xeroxing/printing your password list is also not as benign as it sounds. Any professional copying machines or printer typically includes some sort of non-volatile memory, that could be used to recover recent printouts.