After deliberately resisting the idea of giving games personal rankings/scores for a very long time, I've found myself doing this in recent years for games I've liked and completed. This has been motivated by a desire to organize/understand what I might want to revisit or what similar experiences I might want to seek out. It's also just a fun way keep old games in memory. Do you give your games a personal score or, say, "rank" a bunch of games from best to worst for your personal amusement? (genre lists, franchise lists, developer lists, etc.)
Scoring: Giving a label (typically numeric) as a simple shorthand for how you feel about a game.
Ranking: Putting a group of games (typically related ones) into an ordered list, sorted from best to worst.
Let's discuss how you've gone about doing this, and let's talk about what observations, insights, and problems you might run into.
And at the risk of flooding the conversation with too many things to talk about, I'm going to contribute a wall of text about all of those things. If you are reading this in the future and the thread seemingly moved on to one topic, know that I'm still interested in anything you might have to say about other stuff here that isn't getting as much attention:
I find that starting by ranking all games I like in a given genre (or another broad, genre-like category) to be indisputably the best approach. (I'd be interested in hearing other takes here.) Don't start with scores, just relative ordering. Once I have the ordering, it feels natural to divide it into several tiers and those tiers become something equivalent to my "personal scores".
The thing I don't like about sequentially scoring a list of games (i.e., before they are ordered) is that I feel like I'm concurrently figuring out what those scores mean to me at the same time that I'm adding each additional game. Eventually it feels like I have to go back and adjust my scores... or more likely just abandon the effort because too much arbitrariness has built up!
Rankings, therefore, are very practical because they are easier to do and will eventually lead to scores if I want them. Now, I'm no saint and there's still times where I have to just make a snap judgement and put one game over another, but I move on feeling happy about it which is the difference. It seems to happen most often with games I know I like but don't have good recent memories for.
So how can you easily go from tier rankings to scores? I will call the highest tier to be "score 10" or "score 100". The rankings themselves tend to naturally calibrate the score resolution ("how far apart are adjacent tiers?"), or I can pick a score that feels appropriate for the bottom tier and interpolate upwards for the rest. For example, let's say I have a list with 6 tiers. I'm probably going to name the tiers like this: 100, 95, 90, 85, 80, and 75. These numbers deliberately aren't supposed to represent something absolute (other than "50" being perhaps an average game), which feels liberating. Being able to see how comparatively few games are within a single tier makes me feel just how "unnecessary" it would be think about scores in between these values, so to avoid the nuisance that is where the score resolution ends.
Thoughts on Scoring Systems:
Scores don't have to be numbers, sometimes letter grades (A+, A, B+,...) or word labels (bad < ok < good < excellent < masterpiece) are used. Let's call these "word marker" based systems. Number based systems are vastly more common than word marker ones and I think they have more flexibility for when you want to shift things in the future (changing resolution, for example, or even just splitting one crowded tier into two or three while leaving the rest alone). To me, numbers also avoid the nagging problem that I've already talked about: letting other "absolute meanings" creep into your scores...
This is really getting into the embodied experience of trying to give scores to a slew of games, and I hope people who do personal projects like this can relate...
What I find is that it is hard to separate the words "masterpiece", "A+", "ok", etc. from their English and cultural meaning and you will find your brain's inner voice saying "Mario Bros is an ok game". When this happens, you might immediately & involuntarily start judging whether that "sounds right" in some kind of social context, which I think is mostly unhelpful since verbal conversations always have a very fluid context for what words mean. Numbers can have their own version of this problem, but it's easier for me to stay reminded that they are just relative to one another.
Real World Observations:
One observation I've discovered is how much happier the process of ranking a list of games became when I decided to label my bottom tier as the less nuanced "50-70 tier". It seems unavoidable that the further down you go in your list, the less excited you are about your feelings and thus you aren't as motivated to record precise information. For me, that ends with me not caring about the difference between 50 and 70. I still have the relative ordering within a tier, for what that is worth to me. Games below "50" aren't written down at all in my lists. I want building and maintaining my list to be a joyful activity, and the purpose is to understand what I might like to play or seek out anyway. (It's also nice if the list is pleasant to open up and look through!)
The Rating Process:
Ok, but when you are starting with an unorganized list, how do you actually process your feelings for one game over another? What's the standard? Well, everyone is going to have their own criteria that they, metaphorically, weigh together! And, importantly, everyone will have criteria that are excluded from consideration.
I don't have a scientific process myself, but I can discuss what I choose to let contribute and how I categorize these elements:
My personal connection to a given game always leaps to mind very quickly when I start evaluating it. I definitely choose to let this be a category that has influence where that game goes in the list. I also find myself thinking about "forward-centric" thoughts ... that is, how interested I am towards replaying the game or playing other games like it. In contrast, the "backwards-centric" thoughts would be "what did my past moment-to-moment play experience actually feel like?". As an observation, I feel this last category gets lost more quickly over time. (It becomes harder to judge the farther removed you are.)
I think momentary feelings (literally, the moment-to-moment) explain the phenomena wherein games one has recently played/finished always place higher in lists people create.
Then there's the category of thoughts about the game's "flaws and disappointments". I try not to let this influence my thinking in most cases. If something in this category doesn't actually affect my enjoyment while playing the game then I will discount it and only consider ones that do.
Like all such things the final result is subjective and only a snapshot in time. If this mindset is fully embraced from the start it helps to keep the self-perceived "meaning" of these lists from leaking out completely.