(;SZ[19]GM[1]FF[1]CA[UTF-8]AB[pd][cc][qn][nq][qq][qp][pr][qr][pm][ol][qm][nm][ok][nk][cn][cq][dq][er][fq][gr][fs][ip]AW[pp][dp][ic][oo][pq][mp][or][oq][om][pn][nl][on][mm][ml][eo][cp][eq][ep][dr][cr]GN[2024-01-12-OGS-Tymekeeper-eccles43](;W[re];B[qd](;W[rd]C[RIGHT This is one of several equally good options. See solution for other submarine invasions.])(;W[qg]C[RIGHT This is one of several equally good options. See solution for other submarine invasions.])(;W[qh]C[RIGHT This is one of several equally good options. See solution for other submarine invasions.]))(;W[rd];B[qd](;W[re]C[RIGHT This is one of several equally good options. See solution for other submarine invasions.])(;W[rc];B[qf]TR[nk]TR[ok]TR[ol]TR[pm]TR[qm]C[Good start, but your second move is in the wrong direction!]))(;W[nc];B[nd];W[md];B[ne]TR[ne][nd]LB[re:A]C[Black's right side moyo gets big. Next, KataGo says white should invade at A, but invading before black plays the marked stones would have been more effective.])(;W[qf];B[qe];W[pf];B[nd]TR[pf][qf]C[White's stones are heavy.])(;W[qc];B[qd];W[pc];B[od]TR[qm][ol][ok][nk][pm]C[No, 3-3 invasions are fashionable nowadays, but it doesn't work well with all the marked stones already in place. KataGo rates this as 2 points worse than the recommended move.])(;W[qd];B[qe](;W[re];B[pe];W[rd];B[qg]C[Right general idea, but you can do a little bit better.])(;W[qc];B[re];W[pc];B[od]C[Black's moyo is getting big!]))(;W[pc];B[qd]TR[nk][ok][ol][pm][qm]C[With the marked stones below, black can play this way. It works out the same as a 3-3 invasion. (Black could also play A instead for some more complicated variations!) White can do better.])(;W[pe];B[qe];W[qf];B[qd];W[pf];B[nd](;W[qi]C[Almost but not quite. You reduced black's moyo, but gave away too much territory at the top. You can do better.])(;W[pi]C[Almost but not quite. You reduced black's moyo, but gave away too much territory at the top. You can do better.])))