F2L: stuck pieces and all four pairs

Intruders in the slots

As long as the corner and edge were on top, the tricks and turns of the top were enough. But often a piece is sitting down below. Look at the front-right slot: there's a white corner in it, white side down, just as it should be. Only it's an intruder, the white-green-red corner, whose home is at the front left. And the white-green-orange corner is sitting right there, at the front left. The two corners have swapped homes. Both sit white side down, so from underneath the white face looks complete, as if nothing were wrong.

The rule is simple: anything stuck down below in the wrong place comes up first, using the same three-move trick. Turn the cube with y so the slot holding the intruder is at the front right (here it already is), and lift the piece out.

Lift out, turn, insert

R U′ R′ lifts the white-green-red corner to the top, where it immediately joins its edge. The pair is ready; now turn the cube. After y′, the red center faces you and this pair's slot is at the front right.

But that slot is occupied by the white-green-orange corner. The trick F′ U F does two jobs at once: it inserts the green-red pair and lifts out the white-green-orange corner, which then joins its own edge on top.

One more y, and green faces you again. The ready pair is on top at the front left, lying along the front face, so you can skip the first U: R U′ R′ is enough. Nine moves and two turns of the cube, and both mixed-up slots are solved.

Corner home, edge on top

The corner is already in its slot, the right way around, and the edge is waiting on top. Recognize these moves? U R U' R' U' F' U F is the "right" algorithm from the middle-layer chapter.

Now you can see how it works inside. U R U′ R′ lifts the corner and joins it to the edge. U′ F′ U F inserts the ready pair. Your old algorithm is F2L in miniature: you were building pairs long before you'd heard the word.

Try it yourself: corner home, edge on the left

The corner is home again, the right way around, and the edge is on the left side of the top, green facing up. Start with the front face: U F′ U F lifts the corner, and it joins the edge. And you already know how to insert a ready pair.

A twisted corner

The corner is in its slot, but twisted: white faces right and green faces down. The edge is waiting on the far side of the top. You can't build a pair like this; the corner has to come out.

U′ moves the edge out of the way. F′ U F lifts the corner, which lands above the slot with white facing right, while the edge arrives on the far side. Look familiar? It's the easy case. R U R', and the pair is home.

Try it yourself: a twisted corner

The corner is in its slot with white facing you, and the edge is on the right side of the top. Send the edge to the back with U', then lift the corner out with R U' R'. It lands above the slot with white facing you, and the edge ends up on the left. From there, it's the mirror-image easy case.

Both home, but the edge is flipped

This is the most frustrating case. The corner is in its slot, and even the right way around, but the edge is flipped: orange faces front and green faces right. You can't flip an edge on its own, so both pieces have to come out and the pair has to be built from scratch.

R U′ R′ lifts the corner and edge to the top. U F′ U2 F joins them into a pair. Another U F′ U2 F, and the pair drops into its slot. Eleven moves, and not one new trick.

F2L, start to finish

Remember the cube you built the daisy on? The first F2L chapter started from it too. Skip the daisy, and its cross takes just five moves: D2 R B′ D′ L′. Here is its F2L, all four pairs:

• green-orange: R U R′ joins it, U′ R U2 R′ inserts it;
• blue-red: after y2 it's already a pair, so just R U2 R′;
• blue-orange: y′, then U R U2 R′ joins it, U′ R U2 R′ inserts it;
• green-red: after y2 the corner and edge sit side by side, but they aren't a pair. F′ U F splits them up, and after U2 it's the easy case: R U R′.

That's 25 moves for four pairs. On the same cube, the layer-by-layer method would spend 74 moves on the white corners and middle layer, nearly three times as many.

Tips and what's next

• Start with the easiest pair. Before you turn anything, look around. Maybe a pair is already joined, or already sitting in the easy case.
• Keep your eyes on the cube. As soon as one pair is in, look for the next. Speedcubers call this skill look-ahead.
• Don't be shy about y. It's better to turn the cube one extra time than to reach for a far slot.
• Check your work. The Solve my cube page has an "Intuitive F2L" method. It solves any cube using exactly these tricks and explains every pair.

Common mistakes:

• Missing the intruders. A piece in another pair's slot won't leave on its own. Lift it out first, then build the pair.
• Prying pieces out with random turns. The three-move tricks leave the cross and the finished pairs alone; random turns don't.

With intuitive F2L, you already have half of CFOP: the cross and the pairs. All that's left is the last layer. The next chapter shows how it's solved in two steps, OLL and PLL, and why speedcubers end up learning algorithms after all.