#rikkai

Limitations of categorical stats

The stats do not accurately capture a player’s actual strength. In particular, for Rikkai, the stats do not accurately predict the outcomes of the tiebreaker elimination matches (save for Marui vs Jackal):

However, this analysis, being partly quantitative, necessarily relies on the categorical stats. I make the following assumptions: 

All five stats have equal weight; none is more valuable than the others. 

The stats are objective rather than subjective and thus provide a basis for comparison between players.

For ease of analysis, Kirihara’s total stat is assumed to be 16.5, the average of his normal stats (15) and Devil Mode (18). 

Limitations of analytical approach

This analysis mostly looks at the variety and strength of doubles partners. It does not account for stability/frequency of partnerships (eg. Marui-Jackal and Niou-Yagyuu being the standard doubles pairings).

Similarly, this analysis does not consider the "strength" of the partnership (ie. how good each pair is as a doubles pair). It is difficult to draw meaningful conclusions from win-loss ratio because of small sample sizes, lack of data for certain pairings, and the sheer variety in opponents (eg. a 6-0 win against a weak school doesn’t mean much). Further, some match outcomes are affected by other considerations (eg. Marui and Jackal throwing their D2 match against Nagoya Seitoku). 

That aside, let’s get into the analysis proper. 

**I don’t have a quantitative background, this is entirely just futzing around with the numbers for fun. 

Doubles within the team

The number in brackets indicates the sum of a player’s categorical stats. Again, I followed the order of players as set out in the fanbook, which roughly corresponds to the intra-team hierarchy. 

When making this table, I noticed that the doubles pairings tend to fall along the vertical line from top-left to bottom-right: that is, players generally play doubles with those around their skill level. 

The table is visually separated into two distinct areas: the Yukimura-Sanada-Yanagi vortex in the top-left corner and the rest of the team. Within the team, Yukimura and Sanada have only played doubles with each other and Yanagi. 

Visually, Yanagi-Kirihara (18-16.5) and Yanagi-Jackal (18-15) appear to have the greatest skill gap (3). However, the biggest skill gap is actually Yukimura-Yanagi (23-18) and Sanada-Yanagi (23-18): both have a skill gap of 5. 

The two most stable doubles pairs, Marui-Jackal (17-15) and Niou-Yagyuu (18-17) have a skill gap of 2 and 1 respectively. 

Pairings with a skill gap of 0 are Yukimura-Sanada (23-23), Yanagi-Niou (18-18) and Yanagi-Devil!Kirihara (18-18). Other possible pairings with a skill gap of 0 are Yagyuu-Marui (17-17) and Jackal-Normal!Kirihara (15-15), but there is no official record of them. 

The largest possible skill gap (8) would be Yukimura/Sanada-Jackal (23-15).

All Rikkai regulars have partnered with at least two other players. Niou, Yagyuu, and Jackal have partnered with three others, Yanagi has partnered with five (ie. everyone except Marui and Yagyuu). As a side note, Marui and Yagyuu are the only serve-and-volleyers on the team. Like Inui.

Out of a total of 28 possible doubles pairings amongst the Rikkai regulars, there is an official record for 11 of them, ie. 39.3% of all possible pairings. The average skill gap for these 11 pairings is 1.91.

Doubles within and outside the team 

*Whether Kaidoh is included/excluded as a partner for Yagyuu doesn’t affect the calculation of average (but affects standard deviation). Uncertain whether to include as their doubles partnership was an unofficial match. 

Yukimura, Sanada, and Yagyuu are the only members of the team with a negative average skill gap: that is, on average, they are more skilled than their doubles partners.

Jackal has the smallest spread (1) and standard deviation (0.58). Unless you exclude Yagyuu’s partnership with Kaidoh, Jackal is the only one who has not played doubles with someone outside the team. 

I’ve singled out Yanagi, Niou, and Kirihara’s stats for analysis as they have all played with five or more people and there’s more room for discussion (see below). All three have also partnered with players across all four different playstyles (excluding Akutsu’s “Freestyle” which defies classification). 

Kirihara has the highest average skill gap (5.10) because everyone he’s played with is more skilled than him. He has the second-highest spread (11) behind Niou (12) and ahead of Yanagi (10), and the highest standard deviation (4.72). 

It would be interesting to see where Kirihara goes as a doubles player when he’s not being mentored/guided by a more experienced player. Although I used 16.5 as his average stat, even using his Devil Mode stat of 18, he would still have the highest average skill gap (3.60). 

Yanagi vs Niou

In terms of overall stats, Yanagi (18) and Niou (18) are tied for third place on the team behind Sanada (23) and Yukimura (23). Both have a good claim to being the best doubles players amongst the singles players and the best singles player amongst the doubles specialists. 

Although Yanagi has partnered with more players (7 to Niou’s 6), I think Niou has the stronger claim to being the more versatile doubles player. Niou has the greater spread (12 > 10), the greater standard deviation (4.63 > 4.19), and the greater average skill gap (1.58  > 1.07), suggesting that he’s better able to attract and work with stronger players.

Additionally, Niou’s portfolio has a more balanced mix of playstyles (two counterpunchers, two serve-and-volleyers, one all-rounder, and one aggressive baseliner), probably because Niou himself is an all-rounder. Meanwhile, Yanagi’s portfolio is heavily skewed towards all-rounders (4/7), with only one each from the three other playstyles.

Then again, for their final matches of the NPoT series, Niou, like Sanada, opts to throw his hat in the ring for Team Japan's S1, while Yanagi persuades Yukimura to try for D2. Similarly, for the Nationals finals, Niou and Yanagi take their chances in S2 and D2 respectively. That seems a fair indication of where they prefer to develop as players.

In terms of value-add to the team, Niou contributes a good amount of stability through his regular partnership with Yagyuu. But Yanagi holds the distinction of being the only one who has partnered with Yukimura and Sanada.

Interestingly, within the Rikkai team, Yanagi and Niou have partnered with each other (D1 in Nationals semifinals), but otherwise, their doubles partners are mutually exclusive. Niou has played with Marui and Yagyuu; Yanagi has played with Yukimura, Sanada, Jackal, and Kirihara. 

In conclusion: We were robbed of seeing Yanagi and Niou play D1 against Nagoya Seitoku. It would have been epic.