User 'PeachBlossomGoddess' wrote a great review comparing this drama to the original material. For me, I have never watched or read any of Agatha Christie's works, so I will instead base this review on making direct comparisons to the predecessor, My Roommate is a Detective, and more specifically on the MCs.

Some say "You shouldn't compare these two" to which I say "Why shouldn't we?" Same director, same premise, same setting (just more snow), same character roles, same main lead actors, they are purposefully similar because of the success of MRIAD. A lot of the hype around this drama is from fans of the predecessor. This review is for those who have watched MRIAD and want to know how Checkmate compares.

I'll get some general points out of the way before focusing on the meat, the characters.

Production - Checkmate no doubt wins in quality, but MRIAD production quality is still good enough to enjoy.

Cases - A bit harder to say which is better, it's definitely personal opinion. Checkmate gave a lot more breathing room for cases to unfold, and directly used Agatha's brilliant works, so if anything she should get the credit. Especially the first, Murder on the Orient Express, was so artful and intriguing, no wonder it is her most famous work. But cases started to drag on a bit when they lasted so many eps. On the other hand, MRIAD was all about fast-paced hamminess. The cases were often ridiculous, but as over-the-top it got, it was just so fun to watch it didn't matter how unrealistic it was. I prefer this to Checkmate, though the train case was better than any MRIAD case.

Romance - Checkmate wins hands down. Romance is subtle, mostly makes sense, and doesn't intrude on the plot. (I did skip through the last few eps so unsure how prevalent romance was there) MRIAD romance is a joke. Lu Yao liking Bai Youning? Doesn't make a lick of sense. Fortunately only becomes more prominent in the latter end of the series.

Now to the part where Checkmate really made me want to drop this drama, making it a chore to keep watching.

Characters - MRIAD's characterisation for the two male leads is amazing. 2nd male lead Qiao Chusheng has an interesting dark backstory related to the mafia, influencing his personality in a really unique way and giving a realistic understanding into why he becomes so enamoured with Lu Yao. Female lead is less amazing but has her own weird charm if you can get over her brattiness. All three are given reasonably in-depth backstories. Checkmate characterisation is so average it hurts. There's no love put into them, and it shows. The relationships between the characters also feels forced, put together for plot sake rather than actually enjoying each other's company. Backstories are few, revealed only when involved in cases or in some horribly written way (cough Jin Qiming alcohol scene cough).

This review is already long enough. I'm only going to go into detail on the MC from the respective series.

Backstory
MRIAD MC Lu Yao. A stock department manager from Haining, studied at Trinity College in Cambridge Uni, getting a double degree in maths and medicine. Other tidbits include that he studied law but was too lazy to write a thesis, he's a deacon of UK Freemasonry, and has cut himself off from his very rich and powerful family with ties to the government and military. What I'm saying is, Lu Yao actually has a fully fleshed-out background and existence that explains his personality and motives.

Checkmate MC Situ Yan. A lawyer in Beijing, who studied under a teacher that now lives in Harbin. And... that's it? Maybe I missed something, but for 19+ episodes, this was basically all I knew about the background of Situ Yan. Perhaps they wanted his past to remain mysterious, but it only made him hollow, not really worthy of being a solid MC.

Personality
MRIAD. Lu Yao is a genius. But he is also a cheeky money-lover who wants to live a simple life away from the messiness of politics. He's crass and selfish, a huge troll, super wimpy when confronted with danger, likes solving mysteries to test his intellect and bantering with his companions. He's not a goody-good, but he is on the right side when it counts. Hu Yitian goes above and beyond to craft this multi-faceted character into the charming smartass we all know and love.

Checkmate. At first, I really liked Situ Yan. Dedicated wholeheartedly to justice, mature, calm, intelligent, has OCD. And... and? I enjoyed the first case as it was introducing Situ Yan as a somewhat distant but honest man with amazing reasoning skills. But then... that was all there was. As the episodes went by I found myself feeling more and more despondent at the fact that Situ Yan was so dull and lifeless, like a boring Gary Stu. It's as if his character was just a case-solving medium with no individualism.

I could go on, but this should be enough to prove my points I hope!

For those that read the whole thing, congrats! If you hate my opinion, that's okay! I just wanted to give a genuine analysis on why Checkmate fails to live up to the hype from MRIAD. At the end of the day, it's worth giving it a go so you can judge for yourself.