1) If Oxford wrote any professional plays at all between 1580 and 1602, he would logically have written for his own company, and not for the rival Lord Chamberlain's men.
2) The late Shakespeare plays were performed by the King's men; but Oxford died in 1604, after the King's men had been in existence for little more than a year.
3) Oxford died several years before the registration at the Stationer's Office of King Lear, Troilus and Cressida, Antony and Cleopatra, and Pericles, before the publication of King Lear, Troilus and Cressida, and Pericles, and almost certainly before the composition of The Tempest, which seems to recall events of 1610.
4) The Winter's Tale was first licenced for the stage by Sir George Buc, who did not become stage-licencer until 1610.
5) Oxford's letters betray a faulty command of legal Latin, and are characterized by eccentric orthography and distinct traces of an East Anglian dialect. Thus Oxford spelled likelihoods "leklywhoodes," with the e-for-a and wh-for-h East-Anglian substitution, and he invariably wrote"ofte" for ought - a speech habit mocked as rustic in the Cambridge play of Gammer Gurton's Needle. He wrote "impodent" or "impotent" for impudent, and is the only person in my experience who put an "l" in Wivenhoe, spelling it "Wiuenghole." Oxford's spelling of his own name reflects the three-syllable pronunciation: if Edward de Vere had been their author, Shakespeare's earls would have been not Oxfords but Oxenfords.
6) Oxford's known verse at its worst is pretentious doggerel. He is at his best when translating Italian poetry into English tetrameter.
7) Numerous minor points mesh perfectly with Shakespeare's life but not at all with Oxford's. I would argue, if I had time, that Robert Greene's "upstart crow" of 1592 has a 95 percent chance of referring to the historical William Shakespeare, that A Funeral Elegy of 1612 has a 50-50 chance of being Shakespeare's authentic late work, and that the Passionate Pilgrim fracas of 1612 refers with a 99-44/100 percent certainty to a living - and irate - author whose name was William Shakespeare.
I end on a note of irony: since evidence concerning the historical William Shakespeare is scanty, as they themselves proclaim, Oxfordians cannot prove the historical Shakespeare incapable of having written the plays and poems in the Shakespeare canon; contrariwise, literary historians are swimming in evidence that the 17th earl of Oxford was positively deficient in linguistic skill and high poetic talent.