| B | ↘ | C | cftree got worse |
| ⇢ | B | birch.__extract_features() added | |
| ⇢ | B | cftree.__split_procedure() added | |
| ⇢ | A | cftree.show_feature_destibution() added | |
| ⇢ | A | birch.__decode_data() added | |
| ⇢ | A | cftree.__recursive_get_level_nodes() added | |
| ⇢ | A | cftree.get_level_nodes() added | |
| ⇢ | A | birch.get_noise() added | |
| A | ↘ | B | cftree.__insert_for_leaf_node() got worse |
| B | ↘ | C | birch.__rebuild_tree() got worse |
| C | ↗ | B | birch.process() improved |