diff --git a/src/board.rs b/src/board.rs
index ee96cc4..08eaf0d 100644
--- a/src/board.rs
+++ b/src/board.rs
@@ -146,14 +146,14 @@ impl Board {
 
         let mut chains: Vec<Vec<(usize, usize)>> = Vec::with_capacity(8);
 
-        chains.extend(i_chain.map(|range| range.into_iter().map(|i| (i, j)).collect()));
-
-        chains.extend(j_chain.map(|range| range.into_iter().map(|j| (i, j)).collect()));
+        chains.extend(i_chain.map(|range| range.map(|i| (i, j)).collect()));
+        chains.extend(j_chain.map(|range| range.map(|j| (i, j)).collect()));
 
         // handle diagonals
         chains.extend(diag(i, j, 0, 0, BOARD_SIZE - 1, BOARD_SIZE - 1).map(Iterator::collect));
 
-        let mut fill: Vec<(usize, usize)> = Vec::with_capacity(chains.iter().map(Vec::len).sum());
+        // Longest chain is (BOARD_SIZE - 2) as there needs to be the two pieces containing it
+        let mut fill: Vec<(usize, usize)> = Vec::with_capacity((BOARD_SIZE - 2) * chains.len());
 
         for chain in chains {
             for (chain_length, &(new_i, new_j)) in chain.iter().enumerate() {