Chess Opening Theory/1. e4/1...e5/2. Bc4/2...Nf6/3. f3/3...d5/4. exd5

4. exd5
This move is the best as 4. Bb3 dxe4 5. fxe4 and white's kingside is awkward. Black must now play /4...Nxd5/ as other moves signifies that they are down a pawn. However, /4...Qxd5/ is just an obvious blunder that is only played to make jokes and memes. The best line according to Stockfish is 4...Nxd5 5. d3 Bc5 6. Bxd5 Qxd5 7. Nc3 Qe6 8. Qe2 Nc6 9. Kd1 Qg6 10. h4 h5 11. Nh3 Bf5 12. Nf4 Qg3 13. Nfd5 Nd4 14. Qf1 O-O-O 15. Ne3 Qg6 16. Nxf5 Nxf5 17. Ne4 Ne3+ 18. Bxe3 Bxe3 19. Qe2 Bf4 20. g3 Bh6 21. g4 Bf4 22. a4 Qc6 23. a5 hxg4 24. fxg4 g6 25. Qf3 f5 26. gxf5 gxf5 27. Nd2 Qh6 28. a6 e4 29. Qg2 Rhg8 30. Qf2 e3 31. Qf3 exd2 32. Ra4 Be3 33. Qxb7+ Kd7 34. Qd5+ Ke7 35. Qxf5 Kd6 36. c4 Rgf8 37. Qd5+ Ke7 38. Qe5+ Qe6 39. Ra5 Rxd3 40. Qxc7+ Rd7 41. Qe5 Rf6 42. Qxe6+ Kxe6 43. Ra3 Bh6 44. Ra5 Rdf7 45. Ra1 Rf1+ 46. Ke2 R7f2+ 47. Kd3 Rc1 48. Rd1 Rf3+ 49. Ke2 Re3+ 50. Kf2 Re1 51. Raxc1 Be3+ 52. Kg3 dxc1=Q 53. Rxc1 Bxc1 54. Kf3 Re3+ 55. Kg2 Rb3 56. Kf2 Kd6 57. Kg2 Kc5 58. Kf2 Bh6 59. Ke2 Kxc4 60. Kf2 Kd5 61. Ke2 Bf4 62. h5 Ke4 63. h6 Rxb2+ 64. Kd1 Bxh6 65. Ke1 Kf3 66. Kd1 Rh2 67. Ke1 Rh1#.

'''1. e4 e5 2. Bc4 Nf6 3. f3!? d5! 4. exd5'''