In the case of Hive, HBD is counted as debt. The current debt stands at around 6.3%, with a limit of 30%, after which HBD loses its peg. Two ways conversions are possible for both of the tokens.
In the case of Splinterlands SPS and DEC, there is no such mechanics as debt. DEC is so called product backed stablecoin with a soft peg. Since recently DEC can be created with SPS conversions (burns), that put a cap on the price of DEC on the upside.
Conversions in the other direction, DEC for SPS are not possible, and DEC is defended on the downside by its utility in the game.
The current DEC supply is around 4.6B tokens, or a market cap of 3.8M at the current price. The SPS market cap is at 23M. Combined they have a market cap of 26.8M. This leave us with a debt of around 14%. If the price of SPS increases this will drop and the opposite.
So a 6.3% debt for Hive and a 14% debt for SPS. This comparison might not be as reliable, as the tokens and mechanics are different, but it still gives some sense, where is the DEC market cap to SPS. Another probably more important metric will be to add the market cap (value) of all the Splinterlands assets packs, land, nodes etc, especially the ones that are available to be bought in DEC, since in theory that is the support for DEC on the downside. SPS is only for the upside.