diff --git a/factorio-blueprint-generator/factory_graph_fast_inserter.yml b/factorio-blueprint-generator/factory_graph_fast_inserter.yml
index 748f0ef..bb2ec2e 100644
--- a/factorio-blueprint-generator/factory_graph_fast_inserter.yml
+++ b/factorio-blueprint-generator/factory_graph_fast_inserter.yml
@@ -11,7 +11,7 @@ subfactories:
     recipe: electronic-circuit
     machines: 6
     machine: assembly-machine-3
-  - !BeltPool
+  - !Splitter
   - !SubFactory
     recipe: inserter
     machines: 2
@@ -20,11 +20,16 @@ subfactories:
     recipe: fast-inserter
     machines: 2
     machine: assembly-machine-3
+  - !SideLoader
+  - !ExternalConnection
+    inputs: 1
+    outputs: 8
+  - !SideLoader
 factory_connections:
   - item: iron-gear-wheel
     amount: 5
     from: 0
-    to: 4
+    to: 6
   - item: copper-cable
     amount: 45
     from: 1
@@ -41,3 +46,39 @@ factory_connections:
     amount: 10
     from: 3
     to: 5
+  - item: iron-plate;iron-gear-wheel
+    amount: 10
+    from: 6
+    to: 4
+  - item: iron-plate
+    amount: 5
+    from: 7
+    to: 6
+  - item: iron-plate
+    amount: 15
+    from: 7
+    to: 2
+  - item: inserter
+    amount: 5
+    from: 4
+    to: 8
+  - item: iron-plate
+    amount: 10
+    from: 7
+    to: 8
+  - item: iron-plate;inserter
+    amount: 20
+    from: 8
+    to: 5
+  - item: fast-inserter
+    amount: 5
+    from: 5
+    to: 7
+  - item: copper-plate
+    amount: 22.5
+    from: 7
+    to: 1
+  - item: iron-plate
+    amount: 10
+    from: 7
+    to: 0
diff --git a/factorio-blueprint-generator/src/bin/generate_factory.rs b/factorio-blueprint-generator/src/bin/generate_factory.rs
index 6200eee..4a41ce0 100644
--- a/factorio-blueprint-generator/src/bin/generate_factory.rs
+++ b/factorio-blueprint-generator/src/bin/generate_factory.rs
@@ -29,16 +29,16 @@ fn main() {
     let l = ValidLayout {
         max_tries: 10,
         retries: 20,
-        start_size: Position::new(48, 48),
-        growth: Position::new(0, 0),
+        start_size: Position::new(64, 64),
+        growth: Position::new(4, 4),
     };
 
     let l = GeneticAlgorithm {
         mutation_retries: 20,
-        population_size: 20,
-        population_keep: 1,
-        population_new: 2,
-        generations: 50,
+        population_size: 40,
+        population_keep: 5,
+        population_new: 5,
+        generations: 40,
         valid_layout: l,
     };
     let p = ConflictAvoidance {
diff --git a/factorio-blueprint-generator/src/factory.rs b/factorio-blueprint-generator/src/factory.rs
index 2506812..0311511 100644
--- a/factorio-blueprint-generator/src/factory.rs
+++ b/factorio-blueprint-generator/src/factory.rs
@@ -24,7 +24,7 @@ pub enum Building {
         inputs: usize,
         outputs: usize,
     },
-    BeltPool,
+    Splitter,
     SideLoader,
 }
 
@@ -140,7 +140,40 @@ pub fn generate_factory<L: Layouter, P: Pathfinder>(
                 blueprints.push(blueprint);
                 used_connections.push((0, 0));
             }
-            Building::BeltPool => todo!(),
+            Building::Splitter => {
+                let mut blueprint = Blueprint::new();
+                blueprint.add_entity(Entity::new_splitter(
+                    Beltspeed::Fast,
+                    Position::new(2, 1),
+                    Direction::Up,
+                ));
+
+                blocks.push(MacroBlock {
+                    size: Position::new(2, 1),
+                    input: vec![
+                        Interface {
+                            offset: Position::new(0, 0),
+                            dir: Direction::Up,
+                        },
+                        Interface {
+                            offset: Position::new(1, 0),
+                            dir: Direction::Up,
+                        },
+                    ],
+                    output: vec![
+                        Interface {
+                            offset: Position::new(0, 0),
+                            dir: Direction::Up,
+                        },
+                        Interface {
+                            offset: Position::new(1, 0),
+                            dir: Direction::Up,
+                        },
+                    ],
+                });
+                blueprints.push(blueprint);
+                used_connections.push((0, 0));
+            }
         }
     }
 
diff --git a/factorio-layout/src/genetic_algorithm_v1.rs b/factorio-layout/src/genetic_algorithm_v1.rs
index 84160dd..6d08c2f 100644
--- a/factorio-layout/src/genetic_algorithm_v1.rs
+++ b/factorio-layout/src/genetic_algorithm_v1.rs
@@ -76,7 +76,7 @@ impl Layouter for GeneticAlgorithm {
             if population[0].1 < best_result.1 {
                 best_result = population[0].clone();
             }
-            println!("completed generation {g}\nscore: {}", population[0].1);
+            eprintln!("completed generation {g}\nscore: {}", population[0].1);
         }
 
         Some(best_result.0)