diff --git a/src/complexagent.rs b/src/complexagent.rs
index dc3d4b4..b636e19 100644
--- a/src/complexagent.rs
+++ b/src/complexagent.rs
@@ -12,8 +12,8 @@ pub struct ComplexAgent {
 #[allow(dead_code)]
 impl ComplexAgent {
     pub const fn new(color: Piece) -> Self {
-        const MAX_DEPTH: usize = 18;
-        const NON_LAZY_DEPTH: usize = 5;
+        const MAX_DEPTH: usize = 8;
+        const NON_LAZY_DEPTH: usize = 8;
         Self {
             color,
             future_moves: FutureMoves::new(color, MAX_DEPTH, NON_LAZY_DEPTH),
diff --git a/src/logic/future_moves.rs b/src/logic/future_moves.rs
index 6da7acf..7264245 100644
--- a/src/logic/future_moves.rs
+++ b/src/logic/future_moves.rs
@@ -299,6 +299,44 @@ impl FutureMoves {
         self.refocus_tree();
         self.extend_layers();
         self.compute_values(0..self.arena.len());
+
+        // check arena's consistancy
+        assert_eq!(self.check_arena().join("\n"), "");
+    }
+
+    /// Checks the consistancy of the Arena (parents and children)
+    /// returns a vector of errors ([`String`])
+    pub fn check_arena(&self) -> Vec<String> {
+        let mut errors = vec![];
+        for idx in 0..self.arena.len() {
+            let m = &self.arena[idx];
+            if let Some(parent) = m.parent {
+                if !(0..self.arena.len()).contains(&parent) {
+                    errors.push(format!("{}: parent is out of range ({})", idx, parent));
+                }
+
+                if !self.arena[parent].children.contains(&idx) {
+                    errors.push(format!(
+                        "{}: parent ({}) doesn't list {} as child",
+                        idx, parent, idx
+                    ));
+                }
+            }
+
+            for &child_idx in &m.children {
+                if !(0..self.arena.len()).contains(&child_idx) {
+                    errors.push(format!("{}: parent is out of range ({})", idx, child_idx));
+                }
+
+                if self.arena[child_idx].parent != Some(idx) {
+                    errors.push(format!(
+                        "{}: child ({}) does not list self as parent",
+                        idx, child_idx
+                    ));
+                }
+            }
+        }
+        errors
     }
 
     fn prune_bad_children(&mut self) {