Alex Thach (born November 7, 2008), known online as Alex T, is an American classic Tetris player. He is best known for his victory in the 2024 Classic Tetris World Championships (CTWC), becoming the first person to get a score of over 10 million points, and a number of other smaller records achieved on both original and modified game cartridges which prevent crashes late game.

Thach entered the competitive Tetris scene in 2020 at 11 years old. He originally found success using the "hypertapping" technique of playing but in 2022 adopted the more competitive "rolling" technique as competition improved. Using the new technique, Thach broke multiple records in a more than hour-long game livestreamed on March 11, 2024, where he achieved the highest level reached in one game and a score of more than 10 million, also winning a $2,400 bounty made by the Tetris community for being the first to do so. On June 9, 2024, Thach won the Classic Tetris World Championship (CTWC) after beating two-time former champion Michael Artiaga ("dogplayingtetris"). Thach is also known for his unique and signature victory celebration of dumping Parmesan cheese on his head.

Thach was born on November 7, 2008, and lives in the U.S. state of California. He entered the competitive Tetris scene at 11 years old in 2020, the same year becoming the youngest player to ever maxout out the game's score counter at 999,999 points. Thach became known to the Tetris community because of these achievements, and in 2022, was able to compete in the Classic Tetris World Championship (CTWC), but was eliminated early and placed 16th.

On March 11, 2024, Thach uploaded a photo of a game with a score of 9.9 million points, which surpassed the previous record of 8,952,432 points set by Andrew Artiaga ("PixelAndy") on January 11 earlier in the year. Thach followed this game up by livestreaming a Tetris game lasting slightly over an hour, in which he broke the records for highest level and highest score reached at 235 and 16,248,080 respectively. This game, which was played on a modified game cartridge to suppress crashes that normally occur in later levels of the game, won Thach a $2,600 prize created by the Tetris community for the first person to reach a score of 10 million points. Thach's highest score record was also recognized by Guinness World Records for the NES version of Tetris.

On April 3, 2024, Thach broke the original game cartridge records for highest score reached and latest game crash achieved, simultaneously becoming the fourth person to ever "beat the game" by triggering a killscreen. He also became the first to trigger a rare visual glitch nicknamed "Summoning Satan" by the community. On April 15, 2024, Thach again broke the record for highest score reached on a modified game cartridge after scoring 16,700,760 points. On June 9, 2024, Thach beat two-time previous champion Michael Artiaga ("dogplayingtetris") to earn his first Classic Tetris World Championship title. The golden J-Piece trophy was given to Thach's mother to give to Thach, instead of being awarded by the event's host.

Thach began playing NES Tetris in 2020 using "hypertapping", a technique where the player rapidly vibrates their arm to press the buttons on the controller. This technique was used by Joseph Saelee in his winning 2018 and 2019 CTWC tournaments. Thach found much of his early success with hypertapping, but was compelled to adopt a new technique called "rolling" around 2023 and 2024, as hypertapping was becoming obsolete among top players. Rolling, which was created by fellow Tetris player Christopher Martinez ("Cheez") before the 2020 CTWC, is a technique where the player rolls the back of the controller with all five fingers to position the game pieces more quickly.

In terms of attitude while playing, Thach often makes jokes and uses comedic body language, which he has admitted helps soothe his nerves when getting through difficult levels of the game. Thach has also become well known for destroying his setup and dumping various odd items on his head to celebrate victories, most notably Parmesan cheese. This became his signature victory celebration after he poured the cheese over his head to celebrate beating multiple records in his March 11, 2024, livestream. He continued the tradition after winning the 2024 CTWC, where an inflatable pool was brought out to collect the cheese as he was doused in it by his mother and the hosts of the tournament.

Below is a table of the Tetris tournaments Thach participated in and their outcomes. It should be noted the table is incomplete, as results on the CTM website prior to February 2022 only list the names of the winner and the runner-up.

Year	Tournament	Won-Lost	Finishing place	Ref.
2020	CTM December Challengers Event	4–0	1st
2021	CTM January Futures Event	4–1	2nd
	CTM June Masters Event	3–1	2nd
	Classic Tetris World Championship	2–2	25th
	CTM December Masters Event	4–0	1st
2022	CTM January Masters Event	4–0
	CTM February Masters Event	3–1	2nd
	CTM March Masters Event	2–1	Contender
	CTM April Masters Event	3–1
	CTM June Masters Event	1–1
	CTM July Masters Event	1–1
	CTM August Masters Event	2–1
	CTM September Masters Event	3–1	2nd
	Classic Tetris World Championship	1–1	16th
	CTM December Masters Event	2–1	Contender
2023	CTM January Masters Event	0–1
	CTM Mega Masters	6–0	1st
	CTM Lone Star Championship	3–1	Contender
	CTM August Masters Event	2–1
	CTM September Masters Event	1–1
	CTM October Masters Event	1–1
	CTM November Masters Event	1–1
	Classic Tetris World Championship	2–1
	CTM December Masters Event	3–1	2nd
2024	CTM January Masters Event	2–1	Contender
	CTM February Masters Event	3–1	2nd
	CTM Mega Masters	4–1	Contender
	CTM April Masters Event	4–0	1st
	CTM May Masters Event	4–0
	Classic Tetris World Championship	5–0
	CTM July Masters Event	4–0
	CTM August Masters Event	2–1	Contender
	CTM August DAS Masters Event	0–1