I've been looking at Explainer ratings. Here's an updated list as near as I can make out. After looking at Nicolas' code I still have a number of questions, like:

1) based on the code it looks like a 10 cell Unique Loop should be 4.8, why does it shows up as 5.0?

2) is it possible to have contradiction or double multiple forcing chains?

3) based on the code the x.x9999999999 ratings are just round off errors because of how the ratings are calculated. Is this correct?

4) I didn't go into a lot of detail as to what the complexity truly is. It seems to be related to node count, but there may be something more as well (like maybe the number of chains) so my node counts may be off a little. Any idea how this is really counted? Also I didn't see any differences for ratings of cell, region, contradiction, or double forcing chains in the code. Is there any difference?

CRCD=Cell/Region/Contradiction/Double

UL=Unique Loop

UR=Unique Rectangle

BUG=Bivalue Universal Grave

1.0 Single

1.2 Hidden Single in box

1.5 Hidden Single in line

1.7 Direct Pointing

1.9 Direct Claiming

2.0 Direct Hidden Pair

2.3 Naked Single

2.5 Direct Hidden Triplet

2.6 Pointing

2.8 Claiming

3.0 Naked Pair

3.2 X-Wing

3.4 Hidden Pair

3.6 Naked Triplet

3.8 Swordfish

4.0 Hidden Triplet

4.2 XY-Wing

4.3

4.4 XYZ-Wing

4.5 UR Types 1, 2, 4 or 3 w/ hidden pair

4.6 UR Type 3 w/ naked pair or hidden triplet or UL Types 1, 2, or 4, or 3 w/ hidden pair (6 cells)

4.69 UL Type 3 w/ a naked pair or hidden triplet (6 cells)

4.7 UR Type 3 w/ naked triplet or hidden quad or UL Types 1, 2, 4, or 3 w/ hidden pair (8 cells)

4.8 UR Type 3 w/ naked quad or UL Type 3 w/ naked triplet [or hidden quad] (6 cells) or UL Type 3 w/ naked pair or hidden triplet (8 cells)

4.89 UL Type 3 w/ naked quad (6 cells)

4.9 [UL Type 3 w/ naked triplet or hidden quad (8 cells)]

5.0 Naked Quad or UL 1, 2, or 4 (>=10 cells) (why isn't this 4.8?)

5.1 UL Type 3 w/ naked pair (>=10 cells) (why isn't this 4.9?)

5.2 Jellyfish

5.3

5.4 Hidden Quad

5.5

5.6 BUG Type 1

5.7 BUG Type 2 or 4

5.8 BUG Type 3 w/ naked pair

5.9 BUG Type 3 w/ naked triplet

6.0 BUG Type 3 w/ naked quad

6.1 BUG Type 3 w/ naked quint

6.2 Aligned Pair Exclusion

6.3

6.4

6.5 Bidirectional X-Cycle or Bidirectional Y-Cycle (1-4 nodes)

6.6 Forcing X-chain or Turbot Fish or Bidirectional Y-Cycle (5-6 nodes)

6.69 Forcing X-Chain (7-8 nodes)

6.7 Bidirectional Y-cycle (7-8 nodes)

6.8 Forcing X-Chain or Bidirectional Y-cycle (9-12 nodes)

6.9 Forcing X-Chain or Bidirectional Y-cycle (13-16 nodes)

7.0 Forcing Chain or Bidirectional Cycle (1-4 nodes) or Bidirectional Y-cycle (17-24 nodes)

7.1 Forcing Chain or Bidirectional Cycle (5-6 nodes)

7.2 Forcing Chain or Bidirectional Cycle (7-8 nodes)

7.3 Forcing Chain or Bidirectional Cycle (9-12 nodes)

7.4 Forcing Chain (13-16 nodes)

7.5 Forcing Chain (17-24 nodes) or Aligned Triplet Exclusion

7.6 Forcing Chain (25-36 nodes) or Nishio Forcing Chain (5-6 nodes)

7.7 Nishio Forcing Chain (7-8 nodes)

7.8 Nishio Forcing Chain (9-12 nodes)

7.9 Nishio Forcing Chain (13-16 nodes)

8.0 Nishio Forcing Chain (17-24 nodes)

8.1 Nishio Forcing Chain (25-36 nodes)

8.2 Multiple (7-8 nodes) Region Forcing Chains (is cell, contradiction or double possible?)

8.3 Multiple (9-12 nodes) Cell/Region Forcing Chains

8.4 Multiple (13-16 nodes) Cell/Region Forcing Chains

8.5 Multiple (17-24 nodes) Cell/Region Forcing Chains

8.6 Multiple (25-36 nodes) or Dynamic (5-6 nodes) Cell/Region Forcing Chains

8.7 Dynamic (7-8 nodes) Cell/Region Forcing Chains

8.8 Dynamic (9-12 nodes) CRCD Forcing Chains

8.9 Dynamic (13-16 nodes) CRCD Forcing Chains

9.0 Dynamic (17-24 nodes) CRCD Forcing Chains

9.1 Dynamic (25-36 nodes) CRCD Forcing Chains

9.2 Dynamic (37-48 nodes) CRCD Forcing Chains

9.3 Dynamic (49-72 nodes) or Dynamic + (9-12 nodes) CRCD Forcing Chains

9.4 Dynamic (73-96 nodes) or Dynamic + (13-16 nodes) CRCD Forcing Chains

9.5 Dynamic + (17-24 nodes) CRCD Forcing Chains

9.6 Dynamic + (25-36 nodes) CRCD Forcing Chains

9.7 Dynamic + (37-48 nodes) CRCD Forcing Chains

9.8 Dynamic + (49-72 nodes) CRCD Forcing Chains

9.9 Dynamic + (73-96 nodes) CRCD Forcing Chains

10.0 Dynamic + (97-144 nodes) or Dynamic + Forcing Chains (17-24 nodes) CRCD Forcing Chains

10.1 Dynamic + (145-192 nodes) or Dynamic + Forcing Chains (25-36 nodes) CRCD Forcing Chains

10.2 Dynamic + Forcing Chains (37-48 nodes) CRCD Forcing Chains

10.3 Dynamic + Forcing Chains (49-72 nodes) CRCD Forcing Chains

10.4 Dynamic + Forcing Chains (73-96 nodes) CRCD Forcing Chains

10.5 Dynamic + Forcing Chains (97-144 nodes) CRCD Forcing Chains

10.6 Dynamic + Forcing Chains (145-192 nodes) CRCD Forcing Chains

10.7 Dynamic + Forcing Chains (193-288 nodes) CRCD Forcing Chains

10.8 Dynamic + Forcing Chains (289-384 nodes) CRCD Forcing Chains

10.9 Dynamic + Multiple Forcing Chains (73-96 nodes) CRCD Forcing Chains

11.0 Dynamic + Multiple Forcing Chains (97-144 nodes) CRCD Forcing Chains

11.1 Dynamic + Multiple Forcing Chains (145-192 nodes) CRCD Forcing Chains

11.2 Dynamic + Multiple Forcing Chains (193-288 nodes) CRCD Forcing Chains

11.3 Dynamic + Multiple Forcing Chains (289-384 nodes) CRCD Forcing Chains

11.4 Dynamic + Multiple Forcing Chains (385-576 nodes) CRCD Forcing Chains

11.4 [Dynamic + Dynamic Forcing Chains (73-96 nodes) Region/Contradiction Forcing Chains]

11.5 [Dynamic + Dynamic Forcing Chains (97-144 nodes) Region Forcing Chains]

11.6 [Dynamic + Dynamic Forcing Chains (145-192 nodes) Cell Forcing Chains]

11.7 [Dynamic + Dynamic Forcing Chains (193-288 nodes) Double Forcing Chains]