The Tetrarch showed very little interest in his stud duties (his attitude towards sex was described as being "monastic in the extreme")[4] and as a result sired few foals.

[10] On his final start of the year he contested Britain's most important two-year-old race, the £3,000 Middle Park Stakes over six furlongs at Newmarket and won by six lengths[11] at odds of 1/4.

[13] Some contemporary observers were lavish in their praise for the colt, commenting on his "electrical speed" and the "rhythmic perfection" of his action and describing him as "the best horse of his age... a marvel".

Tetratema appeared to lose his footing in the difficult conditions and although he rallied in the closing stages, he failed by half a length to catch Silvern in a result which was described as a "sensation".

[20] In the aftermath of the race Tetratema retained his position as Derby favourite ahead of Allenby and the Peter Gilpin-trained Sarchedon,[21] and some experts even considered him a likely Triple Crown winner.

[23] Tetratema, the 3/1 favourite, went into an early lead and set an extremely fast pace as he was challenged by Abbot’s Trace (ridden by Steve Donoghue).

[24] Two weeks after the Derby, Tetratema was brought back to sprinting at Royal Ascot and won the Fern Hill Stakes by six lengths from the two-year-old Galway Castle.

When tested over ten furlongs in the Eclipse Stakes however,[25] he again failed to stay and finished unplaced behind the four-year-old Buchan, who won from Silvern and Allenby.

On 28 July he ran in the King George Stakes at Goodwood in which he was opposed by the six-year-old mare Diadem who had won the 1000 Guineas in 1917 before becoming an outstanding sprinter.

[27] Shortly after this race it was reported that McAlmont had refused an offer of £100,000 for the colt which would have more than doubled the highest price ever paid for a British or Irish racehorse.

He was ridden with great confidence by Carslake, who never resorted to the whip as Tetratema won by a length from Orpheus, ending the race as if he had had no more than an exercise gallop.

[32] Although his retirement was announced in August,[33] Tetratema returned to the track in October to end his racing career in the Snailwell Stakes over five furlongs at Newmarket.

The same authors placed him fourth (behind Abernant, Irish Elegance and Pappa Fourway) in their list of British and Irish sprinters and rated him the second best horse foaled anywhere in 1917, four pounds inferior to Man o' War[36] Tetratema was a highly successful breeding stallion, winning the sire's championship in 1929 and finished in the top seven on the sire's list on a total of eleven occasions.